Theriogenology wild最新文献

Molecular characterisation of testicular cells is a pivotal step towards a profound understanding of spermatogenesis and developing assisted reproductive techniques (ARTs) based on germline preservation. To enable the identification of testicular somatic and spermatogenic cell types in felids, we investigated the expression of five molecular markers at the protein level in testes from domestic cats (Felis catus) at different developmental phases (prepubertal, pubertal I and II, postpubertal I and II) classified by single-cell ploidy analysis. Our findings indicate a prominent co-labelling for two spermatogonial markers, UCHL1 and FOXO1, throughout postnatal testis development. Smaller subsets of UCHL1 or FOXO1 single-positive spermatogonia were also evident, with the FOXO1 single-positive spermatogonia predominantly observed in prepubertal testes. As expected, DDX4+ germ cells increased in numbers beginning in puberty, reaching a maximum at adulthood (post-pubertal phase), corresponding to the sequential appearance of labelled spermatogonia, spermatocytes and spermatids. Furthermore, we identified SOX9+ Sertoli cells and CYP17A1+ Leydig cells in all of the developmental groups. Importantly, testes of African lion (Panthera leo), Sumatran tiger (Panthera tigris sumatrae), Chinese leopard (Panthera pardus japonesis) and Sudan cheetah (Acinonyx jubatus soemmeringii) exhibited conserved labelling for UCHL1, FOXO1, DDX4, SOX9 and CYP17A1. The present study provides fundamental information about the identity of spermatogenic and somatic testicular cell types across felid development that will be useful for developing ART approaches to support endangered felid conservation.

Chimaerods represent an enigmatic lineage of cartilaginous fishes and the least studied group within Chondrichthyans. They have a widespread global distribution with a high degree of endemism. In addition, this group has been considered among the least threatened species of Chondrichthyans, but also the most data-deficient group, with biological information lacking for most species. This study represents the first microanatomical, histological, and ultrastructural description of the different stages of folliculogenesis in Callorhinchus callorhynchus, and the first ultrastructural study about this topic within chimaeroids. Specimens of different maturity stages were collected from landings of the commercial fleet operating in San Matías Gulf, Argentina. Folliculogenesis shows some differences compared to other elasmobranchs. Oogonia were present in immature and mature females. Atretic follicles of different sizes were present in mature female ovaries. There is a significant difference between the macroscopic (∼10 mm) and microscopic (∼ 2 mm) follicular size at the beginning of vitellogenesis. There is no evidence of an epigonal organ. The results are discussed in a physiological and reproductive context. This study provides valuable information that will contribute to the understanding of the reproductive biology of the chimaeroids species and its potential for fishery exploitation recovery.

Studies of the reproductive functional morphology of chelonians are important to understand the reproductive physiology, anatomy, and endocrinology of these species. However, data on the reproduction of this group have been difficult to obtain because of their cryptic habits and as a result the consequent inefficiency of conventional field methods in detecting individuals in the wild. In this study, we obtained reproductive organs from 347 adult female yellow-footed tortoises (Chelonoidis denticulatus), one of the most hunted and traded land vertebrates in South America, donated by local sellers in a wild meat market in the Peruvian Amazon. We described the species’ reproductive cycle and the influence of climatic factors on reproductive performance. Of the sampled females, 116 (33.4%) were gravid and 231 (66.6%) were non-gravid, including 215 vitellogenic (62.0%) and 16 non-vitellogenic (4.6%). The mean number of ovarian follicles per female declined from 28.5 (<10 mm diameter), to 7.1 follicles (20–40 mm) to 3.2 follicles> 40 mm. Gravid females had in average 3.7 shelled eggs in the oviduct, with a mean egg diameter of 53.7 mm. The estimated annual reproductive potential in gravid females was 5.1 eggs per clutch, ranging from one to 22 eggs. There was a strong positive relationship between the diameter of shelled eggs and the straight carapace length of gravid females. The final phase of the folicular growth, the most demanding energetic process in chelonian reproduction, correlated with annual rainfall peak, while oviposition was estimated to occur in the dry season. The yellow-footed tortoise should be considered an opportunistic seasonal breeder, though capable of reproducing throughout the year. Reproductive yields are linked to climatic events that influence food availability in the environment. To improve the sustainable use of this species, adult females should be harvested primarily during reproductive quiescence, from the end of the laying period in the late dry season to the mid-rainy season when large follicles appear, to avoid taking gravid females. Our results are useful not just to better understand the reproductive biology of terrestrial chelonians but can inform the conservation management of harvested species.

Humpback whales (Megaptera novaeangliae) in Southeast Alaska have been studied for over 50 years, and are largely considered a recovery success since the cessation of commercial whaling. Reproductive physiology is an important factor to consider in studying population health and can provide important insights into the drivers contributing to population abundance fluctuations. Validated assays for progesterone and testosterone were used on blubber biopsies from humpback whales (N = 33 whales, 71 samples) near Juneau, Alaska, in 2020 and 2021. Long-term sighting histories were used to confirm detected pregnancies with calf sightings the following year. Blubber samples were divided into two seasonal bins (early and late summer). Pregnant females sampled in both early and late summer of both 2020 and 2021 showed elevated progesterone concentrations compared to other reproductive states (p < 0.05). Progesterone concentrations in adult male whales (0.3 ± 0.2 ng/g) were not significantly different from lactating or resting female whales. Blubber testosterone concentrations in adult male humpback whales ranged from 0.05 to 1.1 ng/g, and mean concentrations were approximately double those of female whales in any reproductive state. Pregnancy was detected in 5 of 11 and 4 of 9 adult females in 2020 and 2021 respectively, yielding summer season pregnancy rates for sexually mature females at 0.45, and 0.44, respectively. Calving rates were 0.36 and 0.22 in 2020 and 2021, respectively, and the annual growth rate for this subpopulation was calculated at 2.6 % per annum. One female had successful pregnancies for four consecutive years. These results demonstrate the synergistic value of combining immunoreactive assays and long-term sighting histories to further knowledge of reproductive physiology in individual humpback whales, which can be expanded to assessing the health of a population or ecosystem.

Semen cryopreservation is one common tool for extended genome storage and serves as insurance for declining biodiversity. In the endangered Bornean sun bear, semen was collected with electroejaculation and this is the first attempt at semen cryopreservation for this subspecies. Chilled semen with motility of more than 50 % was extended with Caniplus freezing medium, and cryopreserved with slow freezing protocol. A total of 22 cryopreserved semen straws were evaluated with computer-assisted sperm analysis and conventional semen evaluation tests as well as additional functional tests including evaluation of the acrosome (Rose Bengal Fast Green stain), plasma membrane (hypoosmotic swelling test), and chromatin (toluidine blue stain). Post-thaw semen quality was compromised with poor viability (27.6 ± 11.2 %), motility (8.3 ± 7.1 %), and progressive movement (1.3 ± 2.0 %) but maintained high integrity for the acrosome (71.1 ± 10.8 %), plasma membrane (54.7 ± 9.6 %), and chromatin (89.7 ± 7.6 %). The total post-thaw sperm abnormality was 51.7 ± 10.7 %, predominantly bent tail (28.0 ± 7.6 %) and proximal droplets (20.0 ± 11.8 %). Although this current cryopreservation was not a success, the compromised frozen-thawed semen may be a valuable resource in assisted reproductive technologies such as intracytoplasmic sperm injection. The three additional functional tests demonstrated were simple and affordable and hence are recommended to be part of the routine semen evaluation. Further research is required to develop species-specific cryopreservation protocols and to explore other assisted reproductive technologies in the Bornean sun bear.

For decades, progesterone and its metabolites have served as the primary biomarkers for monitoring reproductive activity in rhinoceroses, whereas protein hormones have received little attention despite their potential value in understanding reproductive function and dysfunction in this taxon. The goals of this study were to: 1) identify an enzyme-linked immunosorbent assay (ELISA) effective in measuring rhinoceros serum prolactin, 2) generate representative prolactin data in male and female rhinoceroses in diverse reproductive states, and 3) characterize prolactin throughout pregnancy in a white rhinoceros that exhibited mid-gestation lactation. Our results indicated that an equine prolactin ELISA by CUSABIO® is effective in measuring serum prolactin concentrations in white, black and Sumatran rhinoceroses. Preliminary data suggested that prolactin is lowest in males and acyclic females, but also appeared low during post-partum lactation. In contrast, prolactin concentrations were elevated in pregnant females and moderate in sexually mature females experiencing reproductive cyclicity. Prolactin increased following conception and generally continued to rise throughout pregnancy in the one pregnant white rhinoceros profiled herein. Spikes and dips in prolactin and progesterone, respectively, were documented around the time of mid-gestation mammary development and colostrum production in this individual and may provide some clues into the physiological triggers of this newly described aberrant reproductive condition. In conclusion, we have identified a new tool for studying reproductive activity in rhinoceroses, generated preliminary data, and revealed an intriguing relationship between prolactin fluctuations and premature lactation. This work provides the foundation for larger, focused studies on the role of prolactin in this taxon.