Genomic insights into Yak (Bos grunniens) adaptations for nutrient assimilation in high-altitudes.

High-altitude environments present formidable challenges for survival and reproduction, with organisms facing limited oxygen availability and scarce nutrient resources. The yak (Bos grunniens), indigenous to the Tibetan Plateau, has notably adapted to these extreme conditions. This study delves into the genomic basis of the yak's adaptation, focusing on the positive selection acting on genes involved in nutrient assimilation pathways. Employing techniques in comparative genomics and molecular evolutionary analyses, we selected genes in the yak that show signs of positive selection associated with nutrient metabolism, absorption, and transport. Our findings reveal specific genetic adaptations related to nutrient metabolism in harsh climatic conditions. Notably, genes involved in energy metabolism, oxygen transport, and thermoregulation exhibited signs of positive selection, suggesting their crucial role in the yak's successful colonization of high-altitude regions. The study also sheds light on the yak's immune system adaptations, emphasizing genes involved in response to various stresses prevalent at elevated altitudes. Insights into the yak's genomic makeup provide valuable information for understanding the broader implications of high-altitude adaptations in mammalian evolution. They may contribute to efforts in enhancing livestock resilience to environmental challenges.

Comparative immunocompetence and interspecies transmission of avian orthoavulavirus-1 in feral birds originating from rural and urban settings.

Feral birds residing close to urban settings exhibit higher immunocompetence against environmental pathogens than their counterparts in rural areas. In this study, we comprehensively evaluated the immunocompetence of five specific feral bird species and investigated the potential for interspecies transmission and pathogenicity of Avian orthoavulavirus-1 (AOAV-1) originating from the Anseriformes order. The immunocompetence assessment involved administering the phytohemagglutinin (PHA) test to individual groups of birds from rural and urban settings, measuring patagium thickness at specific time intervals (12, 24, 36, 48, and 60 h) following the administration of 0.1 mL (1 mg/mL) of PHA. Urban birds displayed significantly enhanced mean swelling responses, particularly urban pigeons, which exhibited a significant difference in patagium thickness at all-time intervals except for 24 h (p = 0.000, p = 0.12). Similarly, rural and urban quails and crows showed substantial differences in patagium thickness at all-time intervals except for 12 h (p = 0.542, p = 0.29). For the assessment of interspecies transmission potential and pathogenicity, each feral bird group was separately housed with naive broiler birds (n = 10 each) and challenged with a velogenic strain of AOAV-1 isolate (Mallard-II/UVAS/Pak/2016) at a dose of 1 mL (108 EID50/mL). Urban birds demonstrated higher resistance to the virus compared to their rural counterparts. These findings highlight the specific immunocompetence of feral bird species and their potential contributions to AOAV-1 transmission and pathogenicity. Continuous monitoring, surveillance, and strict implementation of biosafety and biosecurity measures are crucial for effectively controlling AOAV-1 spillover to the environment and wild bird populations in resource-limited settings, particularly Pakistan.