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This review discusses several research studies that employed comet assay to evaluate the environmental impact of genotoxins in aquatic environments. It focuses on in vivo and in situ studies of aquatic animals. New chemicals are being added each year to the existing burden of toxic substances in the environment. Excessive agricultural and industrial activities adversely affect biodiversity, threatening the survival of species in a particular habitat, as well as posing disease risks to humans. Some of the chemicals, e.g., pesticides and heavy metals, may be genotoxic to the sentinel species and/or to non-target species, causing deleterious effects in somatic or germ cells. Comet assay is a quick, sensitive, and low-cost technique for detecting DNA strand breakage. However, the comet assay has much more to offer than being an assay for testing DNA strand breaks in animal organs. The use of repair enzymes increases the range of DNA lesions that can be detected with the assay. Comparing data from studies that employed different approaches, such as empirical scoring or comet tail lengths, comet assay is one of the challenging techniques to be utilized in environmental studies. The relative amount of DNA in the comet tail indicates DNA break intensity. The assay has been modified to detect various base alterations by including the digestion of nucleoids with a lesion-specific endonuclease. The determination of DNA damage in these indicator species using the comet test would thus offer information on the genotoxic potential of their habitat at an early stage. This would enable intervention techniques to prevent or mitigate adverse health impacts in sentinel animals and humans.

Yak breeding plays a crucial role in sustaining livestock production and ensuring the livelihoods of communities in the mountainous regions of China. With the aim of improving production traits in yaks, this study explores the potential of harnessing genetic diversity and marker-assisted selection (MAS) techniques. The genetic diversity of yak populations is a valuable resource that can be tapped into to enhance desirable traits such as meat quality, milk yield, disease resistance, and adaptability to harsh environments. This study emphasizes the importance of conducting comprehensive genetic characterization of yak populations across different regions in China to identify unique genetic variations and breed-specific traits. Furthermore, the integration of MAS techniques can facilitate the selection of superior individuals for breeding programs. By identifying and utilizing genetic markers associated with desired traits, breeding strategies can be optimized, resulting in accelerated genetic improvement. Various molecular markers, such as single nucleotide polymorphisms (SNPs), microsatellites, and candidate genes, can aid in the identification of economically important traits in yaks. The availability of high-throughput genotyping technologies and advanced statistical models further support the efficient implementation of MAS in yak breeding programs. [ABSTRACT FROM AUTHOR]

The fat content in yak milk is higher than that in dairy cows, but the molecular mechanisms responsible for milk fat synthesis in yaks are still unclear. This study examined the regulatory mechanism of milk fat synthesis in yak mammary epithelial cells (YMECs) by investigating the role of Ribosomal protein L8 (RPL8) in the mTORC1-SREBP1 signaling pathways. The results showed that over-expression or inhibition of RPL8 had a significant effect on triglyceride (TG) secretion, which also affected the sterol regulatory element-binding protein 1 (SREBP1) pathway. Similarly, the intervention of SREBP1 revealed that RPL8 promoted TG secretion through the SREBP1 pathway. Additionally, the study found that over-expression or inhibition of RPL8 regulated the signaling activity of the mammalian target of rapamycin complex 1 (mTORC1), which promoted the SREBP1 signaling pathway through mTORC1. Further examination by over-expressing or inhibiting SREBP1 or mTOR showed that mTOR promoted TG secretion through the mTORC1-SREBP1 signaling pathway. Moreover, YMECs treated with palmitic acid showed increased expression of RPL8, mTOR, and SREBP1, as well as increased TG secretion. Overall, the study's findings provide insights into the underlying mechanisms of milk fat synthesis in yaks, and suggest that the RPL8 gene and mTORC1-SREBP1 signaling pathways could serve as potential genetic markers for milk fat synthesis in yak mammary glands. [ABSTRACT FROM AUTHOR]

The aim of the present study was to perform genetic diversity and population structure estimation on 382 individuals from seven Chinese Tibetan ecotype yak population using twenty-one microsatellites. The results revealed that the HO ranged from 0.4854±0.0194 in NNV to 0.6086±0.0267 in YRY, and the NA ranged from 3.86±1.98 in XMY to 6.05±3.37 in NNV. The least number of markers which deviated from Hardy-Weinberg equilibrium within the population was W, and largest number of deviations was in the NNV population. Consistent of phylogenetic relationships between the seven populations was identified by Phylogenetic N-J network (Reynold’s genetic distance), FST and Principal components factor (PCA) analysis. These analyses inferred that the population cluster data was not only consistent with the populations’ geographic habits but could also be influenced by artificial selection and feeding style. Lastly, two credible genetic backgrounds were identified from the yak populations in this study using STRUCTURE software, which corresponded to previous knowledge about different molecular genetic markers. Therefore, unexpectedly, our study indicated that the diversity of some of the populations was decreased, leaving us to improve and refine our conversional strategy. In addition, this resulted in a greater understanding of human yak phylogenetic differentiation as well as providing data support for understanding the evolution and migration of yak population in future studies. [ABSTRACT FROM AUTHOR]