Cell adhesion and immune response, two main functions altered in the transcriptome of seasonally regressed testes of two mammalian species Real, Francisca M. Lao Pérez, Miguel Burgos Poyatos, Miguel Jiménez Medina, Rafael Barrionuevo Jiménez, Francisco Javier Cell adhesion Immune response Microtus duodecimcostatus Seasonal reproduction Seasonal testis regression Talpa occidentalis Testis transcriptome The authors thank Dr. Slivana Guioli for kindly providing us with the DMRT1 antibody used in this study. This study was funded by the following sources: Spanish Secretaria de Estado de Investigacion, Desarrollo e Innovacion, Ministerio de Econimia y Competitividad (grant number CGL-2015-67108-P), Junta de Andalucia (grant number BIO109), Deutsche Forschungsgemeinschaft (grant numbers MU 880/15-1 and MU 880/27-1), and Helmholtz ERC Recognition Award grant from the Helmholtz-Gemeinschaft (ERC-RA-0033). In species with seasonal breeding, male specimens undergo substantial testicular regression during the nonbreeding period of the year. However, the molecular mechanisms that control this biological process are largely unknown. Here, we report a transcriptomic analysis on the Iberian mole, Talpa occidentalis, in which the desquamation of live, nonapoptotic germ cells is the major cellular event responsible for testis regression. By comparing testes at different reproductive states (active, regressing, and inactive), we demonstrate that the molecular pathways controlling the cell adhesion function in the seminiferous epithelium, such as the MAPK, ERK, and TGF‐β signaling, are altered during the regression process. In addition, inactive testes display a global upregulation of genes associated with immune response, indicating a selective loss of the “immune privilege” that normally operates in sexually active testes. Interspecies comparative analyses using analogous data from the Mediterranean pine vole, a rodent species where testis regression is controlled by halting meiosis entry, revealed a common gene expression signature in the regressed testes of these two evolutionary distant species. Our study advances in the knowledge of the molecular mechanisms associated to gonadal seasonal breeding, highlighting the existence of a conserved transcriptional program of testis involution across mammalian clades. 2022-05-25T08:26:48Z 2022-05-25T08:26:48Z 2022-05-10 journal article Real, F. M... [et al.] (2022). Cell adhesion and immune response, two main functions altered in the transcriptome of seasonally regressed testes of two mammalian species. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, 1– 14. [https://doi.org/10.1002/jez.b.23142] http://hdl.handle.net/10481/74983 10.1002/jez.b.23142 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Wiley