Divergent Seasonal Reproductive Patterns in Syntopic Populations of Two Murine Species in Southern Spain, Mus spretus and Apodemus sylvaticus

In most mammals with seasonal reproduction, males undergo testis regression during the non-breeding period. We performed a morphological, hormonal, functional, and molecular study of the testes of sexually inactive males of two species of murine rodents, the wood mouse, Apodemus sylvaticus, and the Algerian mouse, Mus spretus, in syntopic populations of southern Iberian peninsula. Both species reproduce during most of the year, but wood mice stop breeding in the summer whereas Algerian mice do it in winter. Sexually inactive males of A. sylvaticus show complete testis regression with reduced levels of serum testosterone and abnormal distribution of cell-adhesion molecules. Contrarily, inactive males of M. spretus maintain almost normal spermotogenesis despite a significant reduction of androgenic function. The lack of an evident explanation for the divergent seasonal breeding patterns found in southern populations of A. sylvaticus and M. spretus, compared with northern ones, implies that very subtle species/population-specific features and/or non-conspicuous environmental cues probably operate to determine their seasonal breeding pattern. These results also support the notion that multiple models of circannual testis variation are possible for different populations of the same species, showing that the mechanisms controlling seasonal reproduction are in fact very plastic and fast evolving.

Download Full-text

Interactions between the short-tailed mouse (Mus spretus) and the wood mouse (Apodemus sylvaticus): diet overlap revealed by stable isotopes

Canadian Journal of Zoology ◽

10.1139/cjz-2012-0286 ◽

2013 ◽

Vol 91 (2) ◽

pp. 102-109 ◽

Cited By ~ 11

Author(s):

Sarah Bauduin ◽

Jacques Cassaing ◽

Moussa Issam ◽

Céline Martin

Keyword(s):

Stable Isotopes ◽

Niche Overlap ◽

Wood Mouse ◽

Food Competition ◽

Apodemus Sylvaticus ◽

Mus Spretus ◽

Closely Related Species ◽

Wood Mice ◽

Carbon And Nitrogen ◽

Aggressive Interactions

Extensive niche overlap between closely related species generally leads to aggressive interactions and competition. The short-tailed mouse (Mus spretus Lataste, 1883) and the wood mouse (Apodemus sylvaticus (L., 1758)) show a large habitat overlap without aggressive interactions. The present study investigates the existence of food competition between these species, based on an analysis of carbon and nitrogen stable isotopes. An almost exhaustive sample of plants, which were potential food resources, was taken and analyzed to infer the consumed plants in mouse diets. The main result showed that both species had a similar diet composition, consisting exclusively of seeds and fruits. This suggests that no competition for food between these species is apparent, or if it exists it would be minimized by a differential exploitation of resources. In the absence of food and space competition,the short-tailed mouse may be using the presence of the wood mouse as an indicator of habitat food quality. In the case of wood mice, we hypothesize that the level of competition with short-tailed mice may be low because of the abundance of resources and because the wood mice may perceive the smaller short-tailed mouse as being equivalent to a young of their own species.

Download Full-text

Abundance of the wood mouse Apodemus sylvaticus and the Algerian mouse Mus spretus (Rodentia, Muridae) in different habitats of Northern Algeria

Mammalian Biology ◽

10.1078/1616-5047-00003 ◽

2002 ◽

Vol 67 (1) ◽

pp. 34-41 ◽

Cited By ~ 16

Author(s):

K. Khidas ◽

Nora Khammes ◽

Samia Khelloufi ◽

S. Lek ◽

S. Aulagnier

Keyword(s):

Wood Mouse ◽

Apodemus Sylvaticus ◽

Mus Spretus ◽

Northern Algeria

Download Full-text

Contribution to the knowledge of Apodemus sylvaticus populations in forests of the managed landscape of southern Moravia (Czech Republic)

Journal of Forest Science ◽

10.17221/33/2008-jfs ◽

2008 ◽

Vol 54 (No. 8) ◽

pp. 370-376 ◽

Cited By ~ 2

Author(s):

J. Suchomel

Keyword(s):

Roe Deer ◽

Wood Mouse ◽

Apodemus Sylvaticus ◽

Floodplain Forest ◽

The Body ◽

Additional Food ◽

Artificial Regeneration ◽

Species Population ◽

Southern Moravia ◽

Intensively Managed

The population dynamics of wood mouse (Apodemus sylvaticus) was studied in three forest complexes differing in food supply in the intensively managed landscape of southern Moravia. They included an old semi-natural floodplain forest dominated by oak (HL), production broadleaved forest with the predominance of oak and robinia (HA) and a pheasantry with various forest stands consisting of diverse species and age categories of trees with a quantity of additional food for additional feeding of pheasants and roe deer (RB). The population fluctuation within six-year monitoring was affected by seed years (acorn crops in 2003 and 2006), which resulted in an increase in the species population density in the next year. Statistically significant effects of the crop of acorns on the body weight of monitored species were also detected (P < 0.01, F = 1.44). Relative abundance differed significantly between the floodplain forest (HL) and RB and HA (P < 0.01). The two last-mentioned sites did not differ and only a trend of greater preference to the most variable biotope in RB was noted. It evidences the unsuitability of floodplain forest for the species. In spite of the food specialization in small seeds significant effects of the excess crop of acorns can result in a rapid increase in the Apodemus sylvaticus population which can then cause damage to the natural regeneration of oak or artificial regeneration by seeding although to a substantially smaller extent than the more harmful A. flavicollis.

Download Full-text

Cell adhesion and immune response, two main functions altered in the transcriptome of seasonally regressed testes of two mammalian species

10.1101/2022.01.12.476048 ◽

2022 ◽

Author(s):

Francisca M. Real ◽

Miguel Lao-Perez ◽

Miguel Burgos ◽

Stefan Mundlos ◽

Dario G. Lupianez ◽

...

Keyword(s):

Immune Response ◽

Cell Adhesion ◽

Molecular Mechanisms ◽

Mammalian Species ◽

Gene Expression Signature ◽

Breeding Period ◽

Seasonal Breeding ◽

Analogous Data ◽

Mediterranean Pine ◽

Testis Regression

In species with seasonal breeding, male specimens undergo substantial testicular regression during the non-breeding 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, non-apoptotic 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-beta signalling, 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.

Download Full-text

Mediterranean Pine Vole, Microtus duodecimcostatus: A Paradigm of an Opportunistic Breeder

Animals ◽

10.3390/ani11061639 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1639

Author(s):

Miguel Lao-Pérez ◽

Diaa Massoud ◽

Francisca M. Real ◽

Alicia Hurtado ◽

Esperanza Ortega ◽

...

Keyword(s):

Mammalian Species ◽

Geographic Area ◽

Breeding Period ◽

Functional Regression ◽

The Earth ◽

Poplar Plantations ◽

Microtus Duodecimcostatus ◽

Mediterranean Pine ◽

Animal House ◽

Testis Regression

Most mammalian species of the temperate zones of the Earth reproduce seasonally, existing a non-breeding period in which the gonads of both sexes undergo functional regression. It is widely accepted that photoperiod is the principal environmental cue controlling these seasonal changes, although several exceptions have been described in other mammalian species in which breeding depends on cues such as food or water availability. We studied the circannual reproductive cycle in males of the Mediterranean pine vole, Microtus duodecimcostatus, in the Southeastern Iberian Peninsula. Morphological, hormonal, functional, molecular and transcriptomic analyses were performed. As reported for populations of other species from the same geographic area, male voles captured in wastelands underwent seasonal testis regression in summer whereas, surprisingly, those living either in close poplar plantations or in our animal house reproduced throughout the year, showing that it is the microenvironment of a particular vole subpopulation what determines its reproductive status and that these animals are pure opportunistic, photoperiod-independent breeders. In addition, we show that several molecular pathways, including MAPK, are deregulated and that the testicular “immune privilege” is lost in the inactive testes, providing novel mechanisms linking seasonal testosterone reduction and testis regression.

Download Full-text