{"title":"In the Spotlight-Postdoc.","authors":"Agneesh Barua","doi":"10.1002/jez.b.23277","DOIUrl":"https://doi.org/10.1002/jez.b.23277","url":null,"abstract":"","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142154274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Svetlana V Pavlova, Svetlana A Romanenko, Sergey N Matveevsky, Aleksander N Kuksin, Ivan A Dvoyashov, Yulia M Kovalskaya, Anastasiya A Proskuryakova, Natalia A Serdyukova, Tatyana V Petrova
The subgenus Stenocranius contains two cryptic species: Lasiopodomys gregalis (subdivided into three allopatrically distributed and genetically well-isolated lineages A, B, and C) and Lasiopodomys raddei. To identify karyotype characteristics of this poorly studied cryptic species complex, we used comparative cytogenetic analysis of 138 individuals from 41 localities in South Siberia and Mongolia. A detailed description of the L. raddei karyotype and of the L. gregalis lineage С karyotype is presented for the first time. The A chromosome complement of all examined narrow-headed voles consisted of 2n = 36 and a fundamental number of autosomal arms (FNa) of 50. Between species, patterns of differential staining were similar, though additional C-heterochromatic blocks were found in L. gregalis lineages; Ag-positive nucleolar organizers and ribosomal DNA (rDNA) clusters are located on eight and nine acrocentric pairs, respectively. No B chromosomes (Bs) were found in the Early Pleistocene relic L. raddei, while one to five small heterochromatic acrocentric Bs were detected in all L. gregalis lineages; the number and frequency of Bs varied considerably within lineages, but no intraindividual variation was observed. In both species, telomeric repeats were visualized at termini of all chromosomes, including Bs. The number and localization of rDNA clusters on Bs varied among B-carriers. Immunodetection of several meiotic proteins indicated that meio-Bs are transcriptionally inactive and have a pattern of meiotic behavior similar to that of sex chromosomes (some homology of Bs to sex chromosomes is supposed). The nature, mechanisms of inheritance and stability of Bs in L. gregalis require further investigation.
Stenocranius 亚属包含两个隐居物种:Lasiopodomys gregalis(细分为三个同域分布且基因分离良好的品系 A、B 和 C)和 Lasiopodomys raddei。为了确定这一研究较少的隐蔽物种群的核型特征,我们对来自南西伯利亚和蒙古 41 个地点的 138 个个体进行了比较细胞遗传学分析。我们首次详细描述了 L. raddei 的核型和 L. gregalis С 系的核型。所有受检窄头田鼠的 A 染色体互补体均为 2n = 36,常染色体臂的基本数目(FNa)为 50。不同物种之间的染色差异模式相似,但在 L. gregalis 品系中发现了额外的 C-异染色质块;Ag 阳性的核小体组织者和核糖体 DNA(rDNA)簇分别位于 8 对和 9 对同心圆上。在早更新世遗民 L. raddei 中没有发现 B 染色体(Bs),而在所有 L. gregalis 系中都检测到了 1 至 5 条小的异染色质非中心 Bs;Bs 的数量和频率在系内差异很大,但没有观察到个体内的差异。在这两个物种中,所有染色体(包括 Bs)的末端都能看到端粒重复序列。Bs 上 rDNA 簇的数量和定位在 B 携带者之间存在差异。对几种减数分裂蛋白的免疫检测表明,meio-Bs 的转录不活跃,其减数分裂行为模式与性染色体类似(Bs 与性染色体应该有一定的同源性)。藻胆中 Bs 的性质、遗传机制和稳定性需要进一步研究。
{"title":"Supernumerary Chromosomes Enhance Karyotypic Diversification of Narrow-Headed Voles of the Subgenus Stenocranius (Rodentia, Mammalia).","authors":"Svetlana V Pavlova, Svetlana A Romanenko, Sergey N Matveevsky, Aleksander N Kuksin, Ivan A Dvoyashov, Yulia M Kovalskaya, Anastasiya A Proskuryakova, Natalia A Serdyukova, Tatyana V Petrova","doi":"10.1002/jez.b.23273","DOIUrl":"https://doi.org/10.1002/jez.b.23273","url":null,"abstract":"<p><p>The subgenus Stenocranius contains two cryptic species: Lasiopodomys gregalis (subdivided into three allopatrically distributed and genetically well-isolated lineages A, B, and C) and Lasiopodomys raddei. To identify karyotype characteristics of this poorly studied cryptic species complex, we used comparative cytogenetic analysis of 138 individuals from 41 localities in South Siberia and Mongolia. A detailed description of the L. raddei karyotype and of the L. gregalis lineage С karyotype is presented for the first time. The A chromosome complement of all examined narrow-headed voles consisted of 2n = 36 and a fundamental number of autosomal arms (FNa) of 50. Between species, patterns of differential staining were similar, though additional C-heterochromatic blocks were found in L. gregalis lineages; Ag-positive nucleolar organizers and ribosomal DNA (rDNA) clusters are located on eight and nine acrocentric pairs, respectively. No B chromosomes (Bs) were found in the Early Pleistocene relic L. raddei, while one to five small heterochromatic acrocentric Bs were detected in all L. gregalis lineages; the number and frequency of Bs varied considerably within lineages, but no intraindividual variation was observed. In both species, telomeric repeats were visualized at termini of all chromosomes, including Bs. The number and localization of rDNA clusters on Bs varied among B-carriers. Immunodetection of several meiotic proteins indicated that meio-Bs are transcriptionally inactive and have a pattern of meiotic behavior similar to that of sex chromosomes (some homology of Bs to sex chromosomes is supposed). The nature, mechanisms of inheritance and stability of Bs in L. gregalis require further investigation.</p>","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jessica Fratani, Gabriela Fontanarrosa, Ana Sofía Duport-Bru, Anthony Russell
Digital specializations of geckos are widely associated with their climbing abilities. A recurring feature that has independently emerged within the sister families Gekkonidae and Phyllodactylidae is the presence of neomorphic paraphalanges (PPEs), usually paired, paraxial skeletal structures lying adjacent to interphalangeal and metapodial-phalangeal joints. The incorporation of PPEs into gekkotan autopodia has the potential to modify the modularity and integration of the ancestral limb pattern by affecting information flow among skeletal limb parts. Here we explore the influence of PPEs on limb organization using anatomical networks. We modeled the fore- and hindlimbs in species ancestrally devoid of PPEs (Iguana iguana and Gekko gecko) and paraphalanx-bearing species (Hemidactylus mabouia and Uroplatus fimbriatus). To further clarify the impact of PPEs we also expunged PPEs from paraphalanx-bearing network models. We found that PPEs significantly increase modularity, giving rise to tightly integrated sub-modules along the digits, suggesting functional specialization. Species-specific singularities also emerged, such as the trade-off between the presence of PPEs favoring modularity (along the proximodistal axis) and the interdigital webbing favoring integration (across the lateromedial axis) in the limbs of U. fimbriatus. The PPEs are characterized by low connectivity compared with other skeletal elements; nevertheless, this varies based on their specific location and seemingly reflects developmental constraints. Our results also highlight the importance of the fifth metatarsal in generating a shift in lepidosaurian hindlimb polarity that contrasts with the more symmetrical bauplan of tetrapods. Our findings support extensive modification of the autopodial system in association with the addition of the neomorphic and intriguing PPEs.
壁虎的数字特化与其攀爬能力密切相关。壁虎科(Gekkonidae)和壁虎科(Phyllodactylidae)的姊妹科中独立出现的一个经常性特征是存在新变态的副趾骨(PPEs),通常是成对的副趾骨骨骼结构,位于趾间关节和趾骨-趾骨关节附近。将 PPE 纳入革囊动物的自足茎可能会影响骨骼肢体各部分之间的信息流,从而改变祖先肢体模式的模块性和整合性。在这里,我们利用解剖网络探讨了PPE对肢体组织的影响。我们对祖先没有 PPE 的物种(鬣蜥和壁虎)和有副肢的物种(Hemidactylus mabouia 和 Uroplatus fimbriatus)的前肢和后肢进行了建模。为了进一步阐明 PPE 的影响,我们还从副瓣网络模型中删除了 PPE。我们发现,PPE 显著增加了模块化程度,在指骨上产生了紧密集成的子模块,这表明了功能特化。我们还发现了一些物种特有的奇异现象,例如在 U. fimbriatus 的肢体中,PPE 的存在有利于模块化(沿近侧轴),而趾间蹼则有利于整合(横跨侧内侧轴)。与其他骨骼元素相比,PPE的连接性较低;然而,这种连接性因其具体位置而异,似乎反映了发育限制。我们的研究结果还突显了第五跖骨在造成鳞龙类后肢极性转变方面的重要性,这与四足类更为对称的bauplan形成了鲜明对比。我们的研究结果表明,自足系统的广泛改造与新变态和引人入胜的 PPE 的增加有关。
{"title":"Exploring the Influence of Neomorphic Gekkotan Paraphalanges on Limb Modularity and Integration.","authors":"Jessica Fratani, Gabriela Fontanarrosa, Ana Sofía Duport-Bru, Anthony Russell","doi":"10.1002/jez.b.23275","DOIUrl":"https://doi.org/10.1002/jez.b.23275","url":null,"abstract":"<p><p>Digital specializations of geckos are widely associated with their climbing abilities. A recurring feature that has independently emerged within the sister families Gekkonidae and Phyllodactylidae is the presence of neomorphic paraphalanges (PPEs), usually paired, paraxial skeletal structures lying adjacent to interphalangeal and metapodial-phalangeal joints. The incorporation of PPEs into gekkotan autopodia has the potential to modify the modularity and integration of the ancestral limb pattern by affecting information flow among skeletal limb parts. Here we explore the influence of PPEs on limb organization using anatomical networks. We modeled the fore- and hindlimbs in species ancestrally devoid of PPEs (Iguana iguana and Gekko gecko) and paraphalanx-bearing species (Hemidactylus mabouia and Uroplatus fimbriatus). To further clarify the impact of PPEs we also expunged PPEs from paraphalanx-bearing network models. We found that PPEs significantly increase modularity, giving rise to tightly integrated sub-modules along the digits, suggesting functional specialization. Species-specific singularities also emerged, such as the trade-off between the presence of PPEs favoring modularity (along the proximodistal axis) and the interdigital webbing favoring integration (across the lateromedial axis) in the limbs of U. fimbriatus. The PPEs are characterized by low connectivity compared with other skeletal elements; nevertheless, this varies based on their specific location and seemingly reflects developmental constraints. Our results also highlight the importance of the fifth metatarsal in generating a shift in lepidosaurian hindlimb polarity that contrasts with the more symmetrical bauplan of tetrapods. Our findings support extensive modification of the autopodial system in association with the addition of the neomorphic and intriguing PPEs.</p>","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142107964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hiroki Gotoh, Itsuki Ohtsu, Taichi Umino, Yo Y Yamasaki, Yohei Minakuchi, Takehiko Ito, Atsushi Toyoda, Jun Kitano
Males and females share most of the genome, but many animals show different phenotypes between the sexes, known as sexual dimorphism. Many insect species show extreme sexual dimorphism, including beetles with "weapon traits" represented by extremely developed horns and mandibles. Existing studies of sex-specific development of beetle weapon traits suggest that sex-specific gene expression plays an important role. On the other hand, contributions of the Y-chromosome, which may potentially carry genes necessary for male development, to weapon trait expression have not been examined. In holometabolous insects, including beetles, the feminizing gene transformer (tra) is roughly conserved in its feminizing function. Only females express a functional isoform of Tra, which causes female differentiation. Knocking down tra in females leads to male tissue differentiation, enabling us to analyze male phenotypes in individuals lacking a Y-chromosome (XX-males). In this study, we investigate whether the Y-chromosome is necessary for stag beetles to express male-specific weapon traits by comparing tra-knockdown-induced XX-males with natural XY males. We show that XX-males could express weapons (enlarged mandibles) as in XY-males. These results suggest that the Y-chromosome does not have a major role in weapon trait expression in this species.
雄性和雌性共享大部分基因组,但许多动物在两性之间表现出不同的表型,即所谓的性二态。许多昆虫物种表现出极端的性二态性,包括具有 "武器特征 "的甲虫,其 "武器特征 "表现为极其发达的角和下颚。对甲虫武器特征的性别特异性发育的现有研究表明,性别特异性基因表达起着重要作用。另一方面,可能携带雄性发育所需基因的 Y 染色体对武器性状表达的贡献尚未得到研究。在包括甲虫在内的全代谢昆虫中,雌性化基因转化子(tra)的雌性化功能基本保持不变。只有雌性才能表达 Tra 的功能异构体,从而导致雌性分化。敲除雌性的 Tra 基因会导致雄性组织分化,从而使我们能够分析缺乏 Y 染色体的个体(XX-雄性)的雄性表型。在这项研究中,我们通过比较敲除tra诱导的XX雄性个体和天然XY雄性个体,研究Y染色体是否是锹形虫表达雄性特异性武器特征的必要条件。结果表明,XX雄性能像XY雄性一样表现出武器特征(下颚增大)。这些结果表明,在该物种中,Y染色体在武器性状表达中并不扮演主要角色。
{"title":"Induction of male-like mandibles in XX individuals of a stag beetle by gene knockdown of a feminizer gene transformer.","authors":"Hiroki Gotoh, Itsuki Ohtsu, Taichi Umino, Yo Y Yamasaki, Yohei Minakuchi, Takehiko Ito, Atsushi Toyoda, Jun Kitano","doi":"10.1002/jez.b.23274","DOIUrl":"https://doi.org/10.1002/jez.b.23274","url":null,"abstract":"<p><p>Males and females share most of the genome, but many animals show different phenotypes between the sexes, known as sexual dimorphism. Many insect species show extreme sexual dimorphism, including beetles with \"weapon traits\" represented by extremely developed horns and mandibles. Existing studies of sex-specific development of beetle weapon traits suggest that sex-specific gene expression plays an important role. On the other hand, contributions of the Y-chromosome, which may potentially carry genes necessary for male development, to weapon trait expression have not been examined. In holometabolous insects, including beetles, the feminizing gene transformer (tra) is roughly conserved in its feminizing function. Only females express a functional isoform of Tra, which causes female differentiation. Knocking down tra in females leads to male tissue differentiation, enabling us to analyze male phenotypes in individuals lacking a Y-chromosome (XX-males). In this study, we investigate whether the Y-chromosome is necessary for stag beetles to express male-specific weapon traits by comparing tra-knockdown-induced XX-males with natural XY males. We show that XX-males could express weapons (enlarged mandibles) as in XY-males. These results suggest that the Y-chromosome does not have a major role in weapon trait expression in this species.</p>","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142072999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The origin of morphological innovation has been extensively studied within evolutionary developmental biology (evo-devo). Recent studies have demonstrated that the developmental module for double-layered epithelial outgrowths is conserved between the insect wings and branchiopod crustacean carapace, thereby introducing homology among these diverse structures. However, evo-devo studies on the branchiopod crustacean carapace have been primarily limited to a single species, the water flea Daphnia magna, leaving the gene regulatory network governing carapace development not comprehensively understood. Furthermore, realizator genes downstream of the character identity mechanism (ChIM) for bilayered epithelial development remain inadequately described. In this study, we analyzed tissue-specific transcriptional profiles in the developing longtail tadpole shrimp, Triops longicaudatus. We observed significant upregulation of papilin in the carapace-bearing head, along with its expression in both the carapace and the trunk limb lobes. Based on these results, we hypothesize that differential expression of papilin is involved in the disproportional growth of Triops carapace. Our findings will contribute to elucidating the diversification of double-layered epithelial outgrowths across distant arthropod lineages.
{"title":"Comparative transcriptomics suggests a potential realizator gene for carapace expansion in longtail tadpole shrimp, Triops longicaudatus (Branchiopoda: Notostraca).","authors":"Seunghun Jung, Seojun Kim, Seunggwan Shin","doi":"10.1002/jez.b.23272","DOIUrl":"https://doi.org/10.1002/jez.b.23272","url":null,"abstract":"<p><p>The origin of morphological innovation has been extensively studied within evolutionary developmental biology (evo-devo). Recent studies have demonstrated that the developmental module for double-layered epithelial outgrowths is conserved between the insect wings and branchiopod crustacean carapace, thereby introducing homology among these diverse structures. However, evo-devo studies on the branchiopod crustacean carapace have been primarily limited to a single species, the water flea Daphnia magna, leaving the gene regulatory network governing carapace development not comprehensively understood. Furthermore, realizator genes downstream of the character identity mechanism (ChIM) for bilayered epithelial development remain inadequately described. In this study, we analyzed tissue-specific transcriptional profiles in the developing longtail tadpole shrimp, Triops longicaudatus. We observed significant upregulation of papilin in the carapace-bearing head, along with its expression in both the carapace and the trunk limb lobes. Based on these results, we hypothesize that differential expression of papilin is involved in the disproportional growth of Triops carapace. Our findings will contribute to elucidating the diversification of double-layered epithelial outgrowths across distant arthropod lineages.</p>","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142017638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David Koller, Kevin M Kocot, Bernard M Degnan, Tim Wollesen
The eyes of squids, octopuses, and cuttlefish are a textbook example for evolutionary convergence, due to their striking similarity to those of vertebrates. For this reason, studies on cephalopod photoreception and vision are of importance for a broader audience. Previous studies showed that genes such as pax6, or certain opsin-encoding genes, are evolutionarily highly conserved and play similar roles during ontogenesis in remotely related bilaterians. In this study, genes that encode photosensitive proteins and Reflectins are identified and characterized. The expression patterns of rhodopsin, xenopsin, retinochrome, and two reflectin genes have been visualized in developing embryos of the pygmy squid Xipholeptos notoides by in situ hybridization experiments. Rhodopsin is not only expressed in the retina of X. notoides but also in the olfactory organ and the dorsal parolfactory vesicles, the latter a cephalopod apomorphy. Both reflectin genes are expressed in the eyes and in the olfactory organ. These findings corroborate previous studies that found opsin genes in the transcriptomes of the eyes and several extraocular tissues of various cephalopods. Expression of rhodopsin, xenopsin, retinochrome, and the two reflectin genes in the olfactory organ is a finding that has not been described so far. In other organisms, it has been shown that Retinochrome and Rhodopsin proteins are obligatorily associated with each other as both molecules rely on each other for Retinal isomerisation. In addition, we demonstrate that retinochrome is expressed in the retina of X. notoides and in the olfactory organ. This study shows numerous new expression patterns for Opsin-encoding genes in organs that have not been associated with photoreception before, suggesting that either Opsins may not only be involved in photoreception or organs such as the olfactory organ are involved in photoreception.
{"title":"Developmental gene expression in the eyes of the pygmy squid Xipholeptos notoides.","authors":"David Koller, Kevin M Kocot, Bernard M Degnan, Tim Wollesen","doi":"10.1002/jez.b.23270","DOIUrl":"https://doi.org/10.1002/jez.b.23270","url":null,"abstract":"<p><p>The eyes of squids, octopuses, and cuttlefish are a textbook example for evolutionary convergence, due to their striking similarity to those of vertebrates. For this reason, studies on cephalopod photoreception and vision are of importance for a broader audience. Previous studies showed that genes such as pax6, or certain opsin-encoding genes, are evolutionarily highly conserved and play similar roles during ontogenesis in remotely related bilaterians. In this study, genes that encode photosensitive proteins and Reflectins are identified and characterized. The expression patterns of rhodopsin, xenopsin, retinochrome, and two reflectin genes have been visualized in developing embryos of the pygmy squid Xipholeptos notoides by in situ hybridization experiments. Rhodopsin is not only expressed in the retina of X. notoides but also in the olfactory organ and the dorsal parolfactory vesicles, the latter a cephalopod apomorphy. Both reflectin genes are expressed in the eyes and in the olfactory organ. These findings corroborate previous studies that found opsin genes in the transcriptomes of the eyes and several extraocular tissues of various cephalopods. Expression of rhodopsin, xenopsin, retinochrome, and the two reflectin genes in the olfactory organ is a finding that has not been described so far. In other organisms, it has been shown that Retinochrome and Rhodopsin proteins are obligatorily associated with each other as both molecules rely on each other for Retinal isomerisation. In addition, we demonstrate that retinochrome is expressed in the retina of X. notoides and in the olfactory organ. This study shows numerous new expression patterns for Opsin-encoding genes in organs that have not been associated with photoreception before, suggesting that either Opsins may not only be involved in photoreception or organs such as the olfactory organ are involved in photoreception.</p>","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tijana Vučić, Marija Drobnjaković, Maja Ajduković, Marko Bugarčić, Ben Wielstra, Ana Ivanović, Milena Cvijanović
There is an increased interest in the evolution and development of newts from the genus Triturus because: (1) morphological differentiation among the nine constituent species largely corresponds to different ecological preferences, (2) hybridization between different species pairs has various evolutionary outcomes in terms of life history traits and morphology, and (3) the genus expresses a balanced lethal system that causes arrested growth and death of half of the embryos. These features provide natural experimental settings for molecular, morphological, and life-history studies. Therefore, we produce a staging table for the Balkan crested newt (T. ivanbureschi). We provide detailed descriptions of 34 embryonic stages based on easily observable and interpretable external morphological characters, to ensure reproducibility. Compared with previous staging tables for Triturus, we include a vastly increased sample size and provide high-resolution photographs in lateral, ventral, and dorsal view, complemented by videos of specific developmental periods, and accompanied by detailed explanations on how to delineate the specific stages. Our staging table will serve as a baseline in comparative studies on Triturus newts: an emerging model system in evolutionary and developmental studies.
{"title":"A staging table of Balkan crested newt embryonic development to serve as a baseline in evolutionary developmental studies.","authors":"Tijana Vučić, Marija Drobnjaković, Maja Ajduković, Marko Bugarčić, Ben Wielstra, Ana Ivanović, Milena Cvijanović","doi":"10.1002/jez.b.23269","DOIUrl":"https://doi.org/10.1002/jez.b.23269","url":null,"abstract":"<p><p>There is an increased interest in the evolution and development of newts from the genus Triturus because: (1) morphological differentiation among the nine constituent species largely corresponds to different ecological preferences, (2) hybridization between different species pairs has various evolutionary outcomes in terms of life history traits and morphology, and (3) the genus expresses a balanced lethal system that causes arrested growth and death of half of the embryos. These features provide natural experimental settings for molecular, morphological, and life-history studies. Therefore, we produce a staging table for the Balkan crested newt (T. ivanbureschi). We provide detailed descriptions of 34 embryonic stages based on easily observable and interpretable external morphological characters, to ensure reproducibility. Compared with previous staging tables for Triturus, we include a vastly increased sample size and provide high-resolution photographs in lateral, ventral, and dorsal view, complemented by videos of specific developmental periods, and accompanied by detailed explanations on how to delineate the specific stages. Our staging table will serve as a baseline in comparative studies on Triturus newts: an emerging model system in evolutionary and developmental studies.</p>","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141476677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mai P Tran, Daniel Ochoa Reyes, Alexander J Weitzel, Aditya Saxena, Michael Hiller, Kimberly L Cooper
Vertebrate animals that run or jump across sparsely vegetated habitats, such as horses and jerboas, have reduced the number of distal limb bones, and many have lost most or all distal limb muscle. We previously showed that nascent muscles are present in the jerboa hindfoot at birth and that these myofibers are rapidly and completely lost soon after by a process that shares features with pathological skeletal muscle atrophy. Here, we apply an intra- and interspecies differential RNA-Seq approach, comparing jerboa and mouse muscles, to identify gene expression differences associated with the initiation and progression of jerboa hindfoot muscle loss. We show evidence for reduced hepatocyte growth factor and fibroblast growth factor signaling and an imbalance in nitric oxide signaling; all are pathways that are necessary for skeletal muscle development and regeneration. We also find evidence for phagosome formation, which hints at how myofibers may be removed by autophagy or by nonprofessional phagocytes without evidence for cell death or immune cell activation. Last, we show significant overlap between genes associated with jerboa hindfoot muscle loss and genes that are differentially expressed in a variety of human muscle pathologies and rodent models of muscle loss disorders. All together, these data provide molecular insight into the process of evolutionary and developmental muscle loss in jerboa hindfeet.
{"title":"Gene expression differences associated with intrinsic hindfoot muscle loss in the jerboa, Jaculus jaculus.","authors":"Mai P Tran, Daniel Ochoa Reyes, Alexander J Weitzel, Aditya Saxena, Michael Hiller, Kimberly L Cooper","doi":"10.1002/jez.b.23268","DOIUrl":"https://doi.org/10.1002/jez.b.23268","url":null,"abstract":"<p><p>Vertebrate animals that run or jump across sparsely vegetated habitats, such as horses and jerboas, have reduced the number of distal limb bones, and many have lost most or all distal limb muscle. We previously showed that nascent muscles are present in the jerboa hindfoot at birth and that these myofibers are rapidly and completely lost soon after by a process that shares features with pathological skeletal muscle atrophy. Here, we apply an intra- and interspecies differential RNA-Seq approach, comparing jerboa and mouse muscles, to identify gene expression differences associated with the initiation and progression of jerboa hindfoot muscle loss. We show evidence for reduced hepatocyte growth factor and fibroblast growth factor signaling and an imbalance in nitric oxide signaling; all are pathways that are necessary for skeletal muscle development and regeneration. We also find evidence for phagosome formation, which hints at how myofibers may be removed by autophagy or by nonprofessional phagocytes without evidence for cell death or immune cell activation. Last, we show significant overlap between genes associated with jerboa hindfoot muscle loss and genes that are differentially expressed in a variety of human muscle pathologies and rodent models of muscle loss disorders. All together, these data provide molecular insight into the process of evolutionary and developmental muscle loss in jerboa hindfeet.</p>","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141468502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guillaume Poncelet, Lucia Parolini, Sebastian M Shimeld
Sea squirts (Tunicata) are chordates and develop a swimming larva with a small and defined number of individually identifiable cells. This offers the prospect of connecting specific stimuli to behavioral output and characterizing the neural activity that links these together. Here, we describe the development of a microfluidic chip that allows live larvae of the sea squirt Ciona intestinalis to be immobilized and recorded. By generating transgenic larvae expressing GCaAMP6m in defined cells, we show that calcium ion levels can be recorded from immobilized larvae, while microfluidic control allows larvae to be exposed to specific waterborne stimuli. We trial this on sea water carrying increased levels of carbon dioxide, providing evidence that larvae can sense this gas.
{"title":"A microfluidic chip for immobilization and imaging of Ciona intestinalis larvae.","authors":"Guillaume Poncelet, Lucia Parolini, Sebastian M Shimeld","doi":"10.1002/jez.b.23267","DOIUrl":"https://doi.org/10.1002/jez.b.23267","url":null,"abstract":"<p><p>Sea squirts (Tunicata) are chordates and develop a swimming larva with a small and defined number of individually identifiable cells. This offers the prospect of connecting specific stimuli to behavioral output and characterizing the neural activity that links these together. Here, we describe the development of a microfluidic chip that allows live larvae of the sea squirt Ciona intestinalis to be immobilized and recorded. By generating transgenic larvae expressing GCaAMP6m in defined cells, we show that calcium ion levels can be recorded from immobilized larvae, while microfluidic control allows larvae to be exposed to specific waterborne stimuli. We trial this on sea water carrying increased levels of carbon dioxide, providing evidence that larvae can sense this gas.</p>","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141283805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Žiga Fišer, Hana Whitehorn, Tia Furness, Peter Trontelj, Meredith Protas
Similar phenotypes can evolve repeatedly under the same evolutionary pressures. A compelling example is the evolution of pigment loss and eye loss in cave-dwelling animals. While specific genomic regions or genes associated with these phenotypes have been identified in model species, it remains uncertain whether a bias towards particular genetic mechanisms exists. An isopod crustacean, Asellus aquaticus, is an ideal model organism to investigate this phenomenon. It inhabits surface freshwaters throughout Europe but has colonized groundwater on multiple independent occasions and evolved several cave populations with distinct ecomorphology. Previous studies have demonstrated that three different cave populations utilized common genetic regions, potentially the same genes, in the evolution of pigment and eye loss. Expanding on this, we conducted analysis on two additional cave populations, distinct either phylogenetically or biogeographically from those previously examined. We generated F2 hybrids from cave × surface crosses and tested phenotype-genotype associations, as well as conducted complementation tests by crossing individuals from different cave populations. Our findings revealed that pigment loss and orange eye pigment in additional cave populations were associated with the same genomic regions as observed in the three previously tested cave populations. Moreover, the lack of complementation across all cross combinations suggests that the same gene likely drives pigment loss. These results substantiate a genetic bias in the recurrent evolution of pigment loss in this model system. Future investigations should focus on the cause behind this bias, possibly arising from allele recruitment from ancestral surface populations' genetic variation or advantageous allele effects via pleiotropy.
{"title":"Genetic bias in repeated evolution of pigment loss in cave populations of the Asellus aquaticus species complex","authors":"Žiga Fišer, Hana Whitehorn, Tia Furness, Peter Trontelj, Meredith Protas","doi":"10.1002/jez.b.23256","DOIUrl":"10.1002/jez.b.23256","url":null,"abstract":"<p>Similar phenotypes can evolve repeatedly under the same evolutionary pressures. A compelling example is the evolution of pigment loss and eye loss in cave-dwelling animals. While specific genomic regions or genes associated with these phenotypes have been identified in model species, it remains uncertain whether a bias towards particular genetic mechanisms exists. An isopod crustacean, <i>Asellus aquaticus</i>, is an ideal model organism to investigate this phenomenon. It inhabits surface freshwaters throughout Europe but has colonized groundwater on multiple independent occasions and evolved several cave populations with distinct ecomorphology. Previous studies have demonstrated that three different cave populations utilized common genetic regions, potentially the same genes, in the evolution of pigment and eye loss. Expanding on this, we conducted analysis on two additional cave populations, distinct either phylogenetically or biogeographically from those previously examined. We generated F2 hybrids from cave × surface crosses and tested phenotype-genotype associations, as well as conducted complementation tests by crossing individuals from different cave populations. Our findings revealed that pigment loss and orange eye pigment in additional cave populations were associated with the same genomic regions as observed in the three previously tested cave populations. Moreover, the lack of complementation across all cross combinations suggests that the same gene likely drives pigment loss. These results substantiate a genetic bias in the recurrent evolution of pigment loss in this model system. Future investigations should focus on the cause behind this bias, possibly arising from allele recruitment from ancestral surface populations' genetic variation or advantageous allele effects via pleiotropy.</p>","PeriodicalId":15682,"journal":{"name":"Journal of experimental zoology. Part B, Molecular and developmental evolution","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jez.b.23256","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141198917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}