Active immunization against AMH reveals its inhibitory role in the development of pre-ovulatory follicles in Zhedong White geese
THERIOGENOLOGY
Authors: Chen, R.; Dai, Z. C.; Zhu, H. X.; Lei, M. M.; Li, Y.; Shi, Z. D.
Abstract
The aim of this study was to investigate the effects of active immunization against recombinant Anti-Mullerian hormone (AMH) protein on the ovarian follicular development, egg production, and molecular regulatory mechanisms in broody-prone Zhedong White geese. For this, a recombinant goose AMH protein was expressed using a prokaryotic expression system. Fifty incubating geese from the same genetic background were selected and equally divided into two groups. The immunization group was actively immunized against the recombinant goose AMH protein, whereas the control group was immunized against bovine serum albumin (BSA). Immunization against AMH accelerated ovarian follicular development and increased clutch sizes by one to two eggs in two consecutive laying-incubation cycles. Furthermore, immunization against AMH upregulated the mRNA transcription levels of the FSH-beta gene in the pituitary gland, and FSHR, 3beta-HSD, and Smad4 genes in the granulosa layer of pre-ovulatory follicles; however, immunization downregulated the expression of the OCLN gene in the granulosa layer of pre-ovulatory follicles, and Smad5 and Smad9 genes in the granulosa layer of SYFs. These results suggest that AMH might hinder ovarian follicular development by decreasing both pituitary FSH secretion as well as ovarian follicular sensitivity to FSH. The latter molecular mechanism could be fulfilled by regulating Smad5 or Smad9 signals in SYFs, as well as the FSHR and Smad4 signals that affect progesterone synthesis and yolk deposition in the pre-ovulatory follicles. (C) 2020 Elsevier Inc. All rights reserved.
Full-length transcriptome sequencing and comparative transcriptomic analysis to uncover genes involved in early gametogenesis in the gonads of Amur sturgeon (Acipenser schrenckii)
FRONTIERS IN ZOOLOGY
Authors: Zhang, Xiujuan; Zhou, Jiabin; Li, Linmiao; Huang, Wenzhong; Ahmad, Hafiz Ishfaq; Li, Huiming; Jiang, Haiying; Chen, Jinping
Abstract
Background Sturgeons (Acipenseriformes) are polyploid chondrostean fish that constitute an important model species for studying development and evolution in vertebrates. To better understand the mechanisms of reproduction regulation in sturgeon, this study combined PacBio isoform sequencing (Iso-Seq) with Illumina short-read RNA-seq methods to discover full-length genes involved in early gametogenesis of the Amur sturgeon, Acipenser schrenckii. Results A total of 50.04 G subread bases were generated from two SMRT cells, and herein 164,618 nonredundant full-length transcripts (unigenes) were produced with an average length of 2782 bp from gonad tissues (three testes and four ovaries) from seven 3-year-old A. schrenckii individuals. The number of ovary-specific expressed unigenes was greater than those of testis (19,716 vs. 3028), and completely different KEGG pathways were significantly enriched between the ovary-biased and testis-biased DEUs. Importantly, 60 early gametogenesis-related genes (involving 755 unigenes) were successfully identified, and exactly 50% (30/60) genes of those showed significantly differential expression in testes and ovaries. Among these, the Amh and Gsdf with testis-biased expression, and the Foxl2 and Cyp19a with ovary-biased expression strongly suggested the important regulatory roles in spermatogenesis and oogenesis of A. schrenckii, respectively. We also found the four novel Sox9 transcript variants, which increase the numbers of regulatory genes and imply function complexity in early gametogenesis. Finally, a total of 236,672 AS events (involving 36,522 unigenes) were detected, and 10,556 putative long noncoding RNAs (lncRNAs) and 4339 predicted transcript factors (TFs) were also respectively identified, which were all significantly associated with the early gametogenesis of A. schrenckii. Conclusions Overall, our results provide new genetic resources of full-length transcription data and information as a genomic-level reference for sturgeon. Crucially, we explored the comprehensive genetic characteristics that differ between the testes and ovaries of A. schrenckii in the early gametogenesis stage, which could provide candidate genes and theoretical basis for further the mechanisms of reproduction regulation of sturgeon.