Transcriptome analysis of ovarian maturation in a chondrostei Chinese sturgeon Acipenser sinensis.

Chinese sturgeon (Acipenser sinensis) with an evolutionary history of over 200 million years, has a long lifespan, and an extremely late and asynchronous sexual maturation (8-18 years for males and 14-26 years for females), resulting in the difficulty of mature adult culture. However, little is known about the regulatory mechanisms of the transition among ovarian maturation stages in the Chinese sturgeon. We performed de novo transcriptome sequencing of the Chinese sturgeon at different ovarian maturation stages (FII, FIII, and FIV).

Feedback regulation of 17β-estradiol on two kisspeptin genes in the Dabry's sturgeon (Acipenser dabryanus).

In tetrapods, kisspeptins are a group of peptides that play essential roles in the regulation of the Gonadotropin-releasing hormone secretion, and may participate in the feedback regulation of sex steroids as well. In this study, two kiss paralogs, designated as dskiss1 and dskiss2 were identified in Acipenser dabryanus. The full-length cDNA sequences of dskiss1 and dskiss2 are 1265 and 744 base pairs (bp), encoding 130 and 146 amino acids, respectively.

Establishment of intraperitoneal germ cell transplantation for critically endangered Chinese sturgeon Acipenser sinensis.

Recent progress in germ cell transplantation techniques in fish has paved the way for the conservation of endangered species. Here, we developed an intraperitoneal germ cell transplantation procedure using Chinese and Dabry's sturgeon as donor and recipient species, respectively. Histological analysis revealed that primordial germ cells migrated on the peritoneal wall at 16 days post-hatch (dph) in Dabry's sturgeon.

Identification and sexually dimorphic expression of vasa isoforms in Dabry's sturgeon (Acipenser dabryanus), and functional analysis of vasa 3'-untranslated region.

Germ cells are set aside from somatic cells early in embryogenesis, and are responsible for transmitting genetic information through generations. Vasa is a highly conserved germ cell marker across animal phyla, and widely used to label primordial germ cells. Dabry's sturgeon is a rare and endangered species distributed solely in the Yangtze River basin.

Differential expression of fertility genes boule and dazl in Chinese sturgeon (Acipenser sinensis), a basal fish.

The gene family DAZ (deleted in Azoospermia), including boule, dazl and DAZ, performs highly conserved functions in germ cell development and fertility across animal phyla. Differential expression patterns have been demonstrated for the family members in invertebrates and vertebrates including fish. Here, we report the identification of boule and dazl and their expression at both RNA and protein levels in developing and mature gonads of Chinese sturgeon (Acipenser sinensis).

Identification of a pou2 ortholog in Chinese sturgeon, Acipenser sinensis and its expression patterns in tissues, immature individuals and during embryogenesis.

The class V POU family genes, including pou5f1 and pou2, encode transcription factors critical for the maintenance of pluripotency in embryonic stem cells (ESC) and germ line cells in vertebrates. In the present study, the full-length cDNA of a pou2 ortholog in A. sinensis, Aspou2, was cloned and sequenced.

Molecular characterization and expression pattern of three zona pellucida 3 genes in the Chinese sturgeon, Acipenser sinensis.

Chinese sturgeon (Acipenser sinensis) is a rare and endangered species and also an important resource for the sturgeon aquaculture industry. SMART cDNAs were synthesized from the ovary of A. sinensis, and the full-length cDNAs of three zona pellucida glycoprotein 3 genes (the new gene named AsZP3) were cloned and sequenced.

Molecular and expression analysis of apolipoprotein E gene in the Chinese sturgeon, Acipenser sinensis.

Apolipoproteins are carrier proteins that bind to lipids to form lipoprotein particles and have been shown to play an important role in lipid metabolism. In this study, a full-length cDNA for apolipoprotein E, named AsapoE, was cloned from the Chinese sturgeon (Acipenser sinensis). This cDNA sequence is 1289 bp in length, and codes for a polypeptide of 274 amino acid residues, which is 45% and 42% identical to that of the rainbow trout and zebrafish, respectively, and 39%, 30%, and 29% identical to frog, mouse, and human respectively.

Identification of a vasa homologue gene in grass carp and its expression pattern in tissues and during embryogenesis.

The RNA helicase Vasa is a member of the DEAD box protein family that plays an indispensable role in germ cell determination in eukaryotes such as in Drosophila and Xenopus species. In this study, the grass carp homologue of the Drosophila vasa gene, Civasa (Ctenopharyngodon idella vasa) was obtained using degenerate primers in RT-PCR and 5' and 3' rapid amplification of cDNA end polymerase chain reaction from the grass carp ovary SMART cDNA. This cDNA sequence encodes a 670 amino acid residue protein that contains eight consensus regions for the DEAD box protein family, 9 arginine-glycine repeats and 9 arginine-glycine-glycine repeats, a common character of known Vasa homologues.

Molecular and expression characterization of two somatostatin genes in the Chinese sturgeon, Acipenser sinensis.

Chinese sturgeon (Acipenser sinensis) is a rare and endangered species and also an important resource for the sturgeon aquaculture industry. SMART cDNA was synthesized from the hypothalamus of Chinese sturgeon, and the full-length cDNAs of two somatostatin (SS) genes were cloned and sequenced. The first cDNA (AsSS1) encodes a 116-amino acid protein that contains the SS(14) sequence at its C-terminal extremity.

Differential and spermatogenic cell-specific expression of DMRT1 during sex reversal in protogynous hermaphroditic groupers.

DMRT1 has been suggested to play different roles in sex determination and gonad differentiation, because different expression patterns have been reported among different vertebrates. The groupers, since their gonads first develop as ovary and then reverse into testis, have been thought as good models to study sex differentiation and determination. In this study, we cloned the full-length cDNAs of DMRT1 gene from orange-spotted grouper (Epinephelus coioides), and prepared corresponding anti-EcDMRT1 antiserum to study the relationship of DMRT1 to sex reversal.

Molecular cloning and expression pattern of 14 kDa apolipoprotein in orange-spotted grouper, Epinephelus coioides.

A novel fish-specific apolipoprotein (apo-14 kDa) has been recently cloned from eel and pufferfish. However, its expression pattern has not been elucidated. In this study, EcApo-14 has been screened from hypothalamic cDNA library of male orange-spotted grouper, which shows 62.

Molecular and expression characterization of three gonadotropin subunits common alpha, FSHbeta and LHbeta in groupers.

A SMART cDNA plasmid library was constructed from protogyous greasy grouper (Epinephelus coioides) pituitary, and the full-length cDNAs of three gonadotropin (GTH) subunits common alpha, FSHbeta and LHbeta were cloned and sequenced from the library. The nucleotide sequences of common alpha, FSHbeta and LHbeta subunit cDNAs are 647, 594 and 574 bp in length, and encode for mature peptides of 94, 99 and 115 aa, respectively. High homology was observed by amino acid sequence alignment and identity comparison of the grouper mature peptides of common alpha, FSHbeta and LHbeta with that of other fishes.

Differential expression of thyroid-stimulating hormone beta subunit in gonads during sex reversal of orange-spotted and red-spotted groupers.

We have cloned and characterized the full-length cDNA encoding thyroid-stimulating hormone beta-subunit (TSHbeta) from orange-spotted grouper Epinephelus coioides. It contains 913 nucleotides with an open reading frame encoding 146 amino acids with a 20 amino acid signal peptide. The grouper mature TSHbeta has 75, 70, 61, 59, 41, 42 and 40% identities to that of rainbow trout, Atlantic salmon, zebrafish, European eel, chicken, mouse and human, respectively.