Work

Water homeostasis gene expression in intestines of male and female broilers divergently selected and individually phenotyped for low and high water conversion ratio

Year: 2026

Type: article

Abstract: Background The goal of this study was to evaluate gene expression of water homeostasis-related genes in the intestines of male and female broilers individually phenotyped for low and high water conversion ratio (LWCR and HWCR, respectively). Methods A 2x2 factorial experiment was conducted with male and female broilers from fourth generation LWCR and HWCR lines. From 4 to 6 wk, broilers were housed in cages to phenotype birds for WCR (g water intake/g body weight gain [BWG]) and feed conversion ratio (FCR, g feed intake/BWG). At 6 wk, samples obtained from the upper duodenum, ileum, and cecum (n=5/group) were frozen in liquid nitrogen. Gene expression was determined by RT-PCR for: 1) the arginine vasotocin ( AVT ) system ( AVT , mesotocin [ MT ] and receptors [ VR2, VR1a, VR1b , MTR ]), 2) the renin-angiotensin system (angiotensinogen [ AGT ], angiotensin receptors [ AT1, AT2 ], renin [ REN ], AGT converting enzyme [ ACE ], and Na+/K+ ATPase [ ATP1B1 ], 3) aquaporins ( AQP1–5 and 11), and 4) genes encoding tight junction proteins (occludin, [ OCLN ], and claudins [ CLDN2, CLDN15 ]). Results Gene (mRNA) expression of AVT, VR1a, ACE , and AQP 1,3 and 11 was lower and CLDN2 higher in the LWCR compared to the HWCR line in the upper duodenum. In the ileum, mRNA expression of VR1a and AQP11 was lower, and REN , ATP1B1 and CLDN2 higher in LWCR compared to HWCR broilers. In the cecum, the LWCR line exhibited higher expression of VR2 , ACE , and CLDN15 and lower expression of AGT and AQP 5 compared to HWCR broilers. Female broilers exhibited lower expression of AQP4 in the upper duodenum and lower expression of AGT, REN, ACE, AT1 , and AT2 in the ileum compared to males. In the cecum, females had elevated levels of MTR , AGT , ACE , AT1 , AT2 , AQP1,2,3,4 , and 11, and OCLN and CLDN 2 in the cecum compared to males. Conclusion The results of this study provide insight into water homeostasis gene expression in intestines of male and female broilers divergently selected for LWCR and HWCR. We hope this information will contribute to greater understanding of water homeostasis in broilers and help sustain the broiler industry as water scarcity issues continue worldwide.

Source: Frontiers in Physiology

DOI: 10.3389/fphys.2026.1954752