BMC Zoology最新文献

Background: The wild camel (Camelus ferus) is a globally endangered species, and China has the largest number of wild camels. To determine the current level of genetic diversity of wild camels in various protected areas in China, we collected 30 samples of wild camel feces or tissue (individuals that had died naturally) from the Lop Nur Wild Camel National Nature Reserve, the Annanba Reserve, and the Wuwei Endangered Animal Protection Center.

Results: We obtained mitochondrial CYTB and D-loop sequences of the wild camels and conducted various genetic diversity analyses. The level of genetic diversity among the three groups of wild camels was in the order Lop Nur > Wuwei > Annanba. Three phylogenetic tree (NJ, BI, and ML) using the sequences of both genes indicated that the Annanba samples and some individuals from Lop Nur belonged to the same clade.

Conclusions: Our findings reveal a distinct genetic structure among the reserves and underscore that, despite conservation successes in restoring population numbers, targeted genetic management is crucial to mitigate the risks of genetic erosion and preserve the long-term evolutionary potential of this critically endangered species.

In this study, exons 1, 2, and 3 of the vitamin K epoxide reductase complex subunit 1 (VKORC1) gene, which has been used to indicate anticoagulant rodenticide resistance, were analyzed to investigate whether it is an effective marker for the differentiation of black rats (Rattus rattus Linnaeus, 1758) and brown rats (Rattus norvegicus Berkenhout, 1769) distributed in Anatolia. Although cranial and karyological features distinguish these rat species, morphological discrimination is difficult due to the color variations. In this context, on the basis of the data obtained from genetic diversity values, genetic distance values, Bayesian MCMC dendrograms and Median-joining TCS networks, the Exon 3 region of the VKORC1 gene was determined to function in the discrimination of black and brown rat samples, whereas the Exons 1 and 2 regions did not separate the rat samples via phylogenetic approaches. The results proved that the sequences of the VKORC1 gene in the Exon 3 region are useful as a genetic marker alongside mitochondrial and other nuclear markers for identifying both rat species.

Background: Fishes are key components of the megafauna of the deep sea, and evolutionary adaptations to deep-sea life appear to have occurred independently in at least 22 fish orders. In this context, the analysis of even more fish genomes and mitogenomes has fundamental importance, providing a valuable resource for understanding the molecular mechanisms underlying evolutionary adaptation, especially to extreme environments such as the deep sea. Here, we report the first complete mitochondrial genome of Zu cristatus (Bonelli, 1819), providing essential information on its structure and phylogeny.

Results: After sequencing on the Illumina HiSeq 4000 platform, processing, and assembly via MitoFinder software v.1.4.1, a single circular mtDNA molecule of 17,450 bp in length was annotated. A total of 37 genes were identified, including the first D-loop region for this species. The asymmetry for both AT skews and GC skews is negative, and the AT content is 56.4%. We also detected the presence of 15 small, noncoding, intergenic nucleotide (IGN) regions and some rare stop codons in bony fishes. Pairwise distance and phylogenetic analyses against a list of other mitochondrial sequences from 42 bony fishes confirmed the current phylogeny with previously related orders. EasycodeML analysis revealed that only 4 PCGs underwent positive selection. New questions about the phylogeny of Lampriformes emerged from our phylogenetic analyses of Lampriformes COI.

Conclusion: Overall, the findings of this study highlight the need to elucidate the genetic features of bony fishes in relation to their deep-sea adaptation, with a focus on rare and interesting species.

Background: The Middle Miocene fauna of La Venta, Colombia, offers a grand opportunity to understand low-latitude South American ecosystems prior to the late Cenozoic Great American Biotic Interchange (GABI). We present new material of two proterotheriid litopterns, Villarroelia totoyoi and Mesolicaphrium sanalfonense, and a macraucheniid litoptern, Theosodon, from La Venta. During the GABI, North and South American faunas intermixed, after which some lineages proliferated and others died out. We conducted an ecomorphological analysis of 11 North and South American faunas pre-dating and post-dating the GABI by scoring all mid- to large-sized mammalian herbivores on their body size, tooth morphology, and feeding height.

Results: The fossils studied here offer new information on the deciduous dentition of M. sanalfonense and mandible of the La Venta Theosodon. Pre-GABI South American faunas were more ecomorphologically diverse than their North American counterparts. The post-GABI Pleistocene fauna exhibited similar ecomorphological diversity to pre-GABI South American faunas, but modern faunas show this diversity was mostly lost in the end-Pleistocene extinctions.

Conclusions: The new litoptern fossils provide previously unknown information on these species' morphology, but they do not resolve outstanding systematic and phylogenetic questions. Discrepancies in ecomorphological diversity between pre-GABI North and South American faunas is attributable to the presence of small, high-feeding (arboreal) taxa and hypselodont (ever-growing cheek teeth) taxa in South America, which North America lacked. Arboreal herbivores (porcupines and primates) experienced some success in North America after dispersing during the GABI. Although hypselodont xenarthrans were successful in post-GABI North America, the fact that most other hypselodont lineages went extinct during and after the GABI suggests that dental morphology may not fully capture the ecomorphological diversity in diet of North American herbivores. Future studies could examine faunas immediately before and after the GABI to uncover the precise dynamics of the interchange and why certain lineages succeeded while others failed.

In this study, we report the whole mitochondrial genomes of two species, Meghimatium pictum and Succinea arundinetorum, which belong to Stylommatophora, one of the most abundant orders of Gastropoda. The total sizes of M. pictum and S. arundinetorum mitogenomes are 14,352 bp and 15,282 bp, with surprisingly biased proportions of A+T contents of 72.1% and 76.78%, respectively. The protein coding genes (PCGs) in two mitogenomes show negative AT skew values and evolved primarily under purifying selection. Compared with the ancestor of Stylommatophora, the mitochondrial genes of M. pictum exhibited multiple rearrangement events, while the mitochondrial genes of S. arundinetorum showed only minor differences. Moreover, the order of PCGs was conserved, while the tRNA genes showed high frequency of rearrangement among the Stylommatophora species, suggesting that the latter could be one of the major driving forces of mitogenomic evolution in terrestrial Mollusca species. Our research lays a theoretical foundation for investigating the evolution and divergence of mitochondrial genes and provides valuable resources for studying evolutionary genetics in Stylommatophora species.