A 66-bp deletion in growth hormone releasing hormone gene 5'-flanking region with largemouth bass recessive embryonic lethal.
Growth hormone releasing hormone (GHRH) regulates the secretion of growth hormone (GH) in the pituitary gland. A 66-bp deletion (c.-923_-858del) was detected in the 5'-flanking sequence of the largemouth bass (Micropterus salmoides) GHRH gene. In two cultured random populations of adult individuals (A: n = 170 and B: n = 150), the genotype ratios of +/+:+/- were 2.5:1 and 2.8:1 respectively. Only one -/- fish was detected. A Largemouth bass family was constructed with two heterozygous individuals (+/-) as parents. The genotype ratio of +/+:+/-:-/- in the filial generation embryos was 1:1.6:0.1 at the neurula and 1:2:0 at hatched larvae stages. This indicated that the 66-bp deletion was a recessive lethal site and that homozygous individuals (-/-) died off in embryonic development. The growth traits (body weight, body length and body depth) were measured, and the GHRH mRNA expression levels in brain tissue were detected using real-time PCR. The effects of genotype (+/-) on growth traits and GHRH mRNA expression were not significant. Although the cause of death was not clear, the results hint that the 66-bp deletion site in GHRH 5'-flanking sequence significantly affects the livability in largemouth bass embryonic development.
['Ma|D M|DM|', 'Han|L Q|LQ|', 'Bai|J J|JJ|', 'Li|S J|SJ|', 'Fan|J J|JJ|', 'Yu|L Y|LY|', 'Quan|Y C|YC|']
D000818:Animals D001483:Base Sequence D001492:Bass D029941:Fish Proteins D013007:Growth Hormone-Releasing Hormone D008969:Molecular Sequence Data D060888:Real-Time Polymerase Chain Reaction D017384:Sequence Deletion
Micropterus salmoides recessive lethal livability homozygous lethal indel site