Molecular Characterisation, Tissue Distribution, and Expression Profiling of the Cathepsin B Gene during Ovarian Follicle Development in Geese

ABSTRACT

1. Although there is evidence that Cathepsin B (CTSB) regulates the degradation and absorption of yolk precursors during avian ovarian follicle development, nothing is known about its molecular characteristics, tissue distribution or expression profiles in goose ovarian follicular compartments.

2. The intact 1023 bp coding sequence of the goose CTSB gene was obtained for the first time. It encoded a polypeptide of 340 amino acids (AA) containing two conserved functional domains (i.e., Propeptide_C1 and Peptidase_C1A_Cathpsin B) and three active amino acid residues (+108, +279, and +299). Both the nucleotide and AA sequences of goose CTSB gene showed more than 90% similarity with its respective homologs from other avian species.

3. The qRT-PCR results showed that CTSB mRNA was ubiquitously expressed in all examined goose tissues, with moderate to high levels in the reproductive organs including the ovarian stroma and oviduct.

4. Expression of goose CTSB mRNA in the granulosa layers increased gradually from the 2–4 mm F5 follicles but declined to relatively low levels in the F4-F1 follicles while remaining statistically unchanged in the theca layers throughout follicle development.

5. High sequence similarity of goose CTSB gene to other avian species suggested functional conservation of avian CTSB genes, and its fluctuating levels in the granulosa layers may be associated with the orderly progression of goose follicle development. These data laid a foundation for further elucidating the role of CTSB in the avian ovary.

KEYWORDS:

• Goose
• ctsb
• molecular cloning
• expression profiling
• follicle development

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [31802064]; China Agricultural Research System [CARS-42-4].

Notes on contributors

S. Hu

Conceptualisation, Shenqiang Hu; Data curation, Shenqiang Hu, Huiling Gong, and Jiaran Zhu; Funding acquisition, Shenqiang Hu and Jiwen Wang; Investigation, Shenqiang Hu, Huiling Gong, Jiaran Zhu, Yujing Rong, Yiting Zhao and Yao Lu; Methodology, Shenqiang Hu, Huiling Gong, Jiaran Zhu, and Yujing Rong; Project administration, Shenqiang Hu and Jiwen Wang; Resources, Shenqiang Hu, Liang Li, and Jiwen Wang; Supervision, Shenqiang Hu and Jiwen Wang; Visualisation, Shenqiang Hu, Huiling Gong, and Jiaran Zhu; Writing – original draft, Shenqiang Hu and Huiling Gong; Writing, reviewing and editing; Shenqiang Hu and Jiwen Wang.