Transcriptome dynamics in developing testes of domestic cats and impact of age on tissue resilience to cryopreservation

Andreia M Da Silva,Pierre Comizzoli,Olga Amelkina,Alexandre R Silva

doi:10.1186/s12864-021-08099-8

Abstract

BackgroundFundamental knowledge of cellular and molecular mechanisms in developing testicular tissues is critical to better understand gonadal biology and responses to non-physiological conditions. The objective of our study was to (1) analyze transcriptome dynamics in developing testis of the domestic cat and (2) characterize age effects on the initial response of the tissue to vitrification. Tissues from adult and juvenile cats were processed for histology, DNA integrity, and RNA sequencing analyses before and after vitrification.ResultsTranscriptomic findings enabled to further characterize juvenile period, distinguishing between early and late juvenile tissues. Changes in gene expression and functional pathways were extensive from early to late juvenile to adult development stages. Additionally, tissues from juvenile animals were more resilient to vitrification compared to adult counterparts, with early juvenile sample responding the least to vitrification and late juvenile sample response being closest to adult tissues.ConclusionsThis is the first study reporting comprehensive datasets on transcriptomic dynamic coupled with structural analysis of the cat testis according to the age and exposure to cryopreservation. It provides a comprehensive network of functional terms and pathways that are affected by age in the domestic cat and are either enriched in adult or juvenile testicular tissues.

Highlights

Fundamental knowledge of cellular and molecular mechanisms in developing testicular tissues is critical to better understand gonadal biology and responses to non-physiological conditions
Tissues from juvenile animals were more resilient to vitrification compared to adult counterparts, with early juvenile sample responding the least to vitrification and late juvenile sample response being closest to adult tissues
Sertoli cell maturation The present study reports downregulation of functional terms and pathways related to immune response in late compared to early juvenile period, which coincided with the emergence of more spermatocytes and spermatids, as well as the decrease in anti-Mullerian hormone (AMH) expression

Summary

Introduction

Fundamental knowledge of cellular and molecular mechanisms in developing testicular tissues is critical to better understand gonadal biology and responses to non-physiological conditions. The objective of our study was to (1) analyze transcriptome dynamics in developing testis of the domestic cat and (2) characterize age effects on the initial response of the tissue to vitrification. Cat spermatogenic function reaches maturity at the age of 8 to 10 months, with initial activation and first signs of spermatogenesis at 5 to 6 months [8, 9] This is fundamentally different from the mouse model (spermatogonia begin to differentiate shortly after birth resulting in a synchronous first wave of spermatogenesis) and closer to humans, where spermatogonia are maintained. We still lack deeper knowledge on molecular processes happening during testis maturation in cats, as well as the understanding of differences between immature (neonatal), maturing (pre-, peri-, pubertal), and fully mature (adult) testicular tissue. The only existing RNA-seq study on cat testicular tissue used three adult males over 2 years old and focused on comparison with sterile hybrids [19]

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