Identical sequences but different expression patterns of Hira gene in gynogenetic and gonochoristic crucian carps

Abstract

Hir/Hira (histone regulation) genes were first identified in yeast as negative regulators of histone gene expression. It has been confirmed that HIRA is a conserved family of proteins present in various animals and plants. In this paper, the cDNAs of the Hira homolog named CagHira and CaHira were isolated from gynogenetic gibel carp (gynocarp) and gonochoristic color crucian carp (gonocarp) respectively. The full-length CagHira is 3,860 bp in length with an open reading frame (ORF) of 3,033 bp that encodes 1,011 amino acids, while the full-length CaHira is 3,748 bp in length and also has an ORF of 3,033 bp. The deduced amino acid sequences of both Hira homologs contain seven WD domains and show high identity with other HIRA family members. RT-PCR analyses revealed strong expression of Hira in the ovaries, whereas no expression was detected in the testes of either of the fishes. Hira transcription was not detected in the liver of gyno-carp, but a high level of Hira mRNA was observed in gono-carp. The temporal expression pattern showed that the Hira mRNA is consistently expressed during all embryonic development stages in gyno-carp. However, the abundance of CaHira mRNA significantly decreased (P < 0.05) shortly after fertilization and then increased again and remained stable from gastrula till hatching. The varying spatiotemporal expression patterns of Hira genes in gyno-carp and gono-carp may be associated with the differing reproductive modes used by these two closely related fishes. Our results suggest that Hira may play a role not only in the decondensation of sperm nucleus and the formation of pronucleus during fertilization, but also in gastrulation and the subsequent development of embryos.

Analysis of the toxicogenomic effects of exposure to persistent organic pollutants (POPs) in Slovakian girls: Correlations between gene expression and disease risk

“…An animal study has provided evidence supporting the observed associations between behavioral and learning disabilities and prenatal exposure to PCBs in humans (Nakagami et al, 2011). Du et al (2008) showed in an animal model that HIRA may play a role in the development of embryos.…”

WD Repeat‐containing Protein 73, A Novel Gene Correlated with Gonad Development in Large Yellow Croaker, Larimichthys crocea

“…), suggesting that wdr73 is related to gonad development, similar to that in humans. In some other fishes, WD domain‐containing genes were also found expressed in ovaries (Du et al ; Reading et al ), but not in testis (Du et al ). Yet, the high expression of Lcwdr73 mRNA in ovaries in this study may suggest that it is likely to be a maternal gene, because the egg is considered to be a transcriptionally inactive cell, acting as a storehouse of specific maternal RNAs, proteins, and other molecules required for competency for fertilization, initiation of zygotic development, and transition to embryonic gene expression (Knoll‐Gellida et al ; Knoll‐Gellida and Babin ).…”

Identification and molecular characterization of a receptor-like protein kinase gene from Corchorus capsularis

“…However, this is not an uncommon phenomenon. Previous studies of different species have shown the presence of structurally similar genes with different patterns of expression (37,38).…”