Small intestine structural and functional responses to environmental heavy metal stress in tree sparrow Passer montanus nestlings.

Tree sparrow nestlings predominantly consume protein-rich insect larvae, making them vulnerable to environmental heavy metal contamination through the food web, potentially affecting their growth. Understanding the effects of heavy metals on the structure and function of the small intestine, the principal organ responsible for protein digestion and absorption, is therefore crucial. This study investigated tree sparrow nestlings at three developmental stages (3, 6, and 12 days old) in Liujiaxia (LJX), a comparatively unpolluted area, and Baiyin (BY), a heavy metal polluted area, to elucidate the factors and mechanisms by which heavy metals affect nutrient absorption.

New genes driven by segmental duplications share a testis-specific expression pattern in the chromosome-level genome assembly of tree sparrow.

Based on a chromosome-level genome assembly, a burst of new genes with different structures but a similar testis-specific expression pattern was detected in tree sparrow.