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Correa LA, Aspillaga-Cid A, Riquelme J, Ly-Prieto Á, Hayes LD, Ebensperger LA. Activational and organizational effects of testosterone on the number of mating partners and reproductive success in males of a social rodent. Horm Behav 2024; 165:105613. [PMID: 39121710 DOI: 10.1016/j.yhbeh.2024.105613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/08/2024] [Accepted: 07/27/2024] [Indexed: 08/12/2024]
Abstract
The timing of exposure to the steroid hormone, testosterone, produces activational and organizational effects in vertebrates. These activational and organizational effects are hypothesized to relate with the number of female mating partners and reproductive success in males. We tested this hypothesis by examining 151 wild degu (Octodon degus) males across a 10-year study. We quantified the association between adult serum testosterone levels (i.e., an indirect index of adult activational effects) and anogenital distance (AGD) length (i.e., a direct index of fetal organizational effects), and their interaction on the number of female mating partners and reproductive success. We found no evidence of an association between adult male serum testosterone levels and the number of female mating partners, or between adult male serum testosterone levels and reproductive success. However, male AGD was positively associated with reproductive success, but not so with the number of female mating partners. Additionally, the positive association between male AGD and male reproductive success was mediated by the number of mates. Our findings do not support major roles of activational or organizational effects of testosterone on the number of female mating partners and its consequences on male reproductive success. Instead, our results suggest that compared with individual male attributes, the female social environment plays a more important role in driving male reproductive success.
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Affiliation(s)
- Loreto A Correa
- Escuela de Medicina Veterinaria, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Camino la Pirámide 5750, Huechuraba, Santiago, Chile.
| | - Antonia Aspillaga-Cid
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Juan Riquelme
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Álvaro Ly-Prieto
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Loren D Hayes
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
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2
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Correa LA, Aspillaga-Cid A, Bauer CM, Silva-Álvarez D, León C, Ramírez-Estrada J, Soto-Gamboa M, Hayes LD, Ebensperger LA. Social environment and anogenital distance length phenotype interact to explain testosterone levels in a communally rearing rodent: Part 1: The male side. Horm Behav 2024; 160:105479. [PMID: 38278060 DOI: 10.1016/j.yhbeh.2024.105479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 01/28/2024]
Abstract
In vertebrates, male testosterone levels vary across the year being generally higher during the mating season relative to the offspring rearing season. However, male testosterone levels may also be associated with male anogenital distance (AGD) length (a proxy of prenatal androgen exposition), and influenced by the social group environment. In social species, it has been proposed that high levels of testosterone could be incompatible with the development of an amicable social environment. Thus, in these species, it is predicted that males have relatively low levels of testosterone. Our goal was to examine the potential association between male serum testosterone levels, season, male AGD length, and the social environment in the rodent Octodon degus under natural conditions. We quantified male serum testosterone levels during the mating and offspring rearing seasons, and we determined the number of females and males in each social group, as well as the composition of groups, in terms of the AGD length of the female and male group mates, from 2009 to 2019. Our results revealed that male testosterone levels covary with season, being highest during the offspring rearing season. Additionally, male testosterone levels vary with male AGD length, and female and male social group environments. More importantly, male degus exhibit low levels of testosterone that are indistinguishable from female levels during offspring rearing season. Similar to other highly social mammals, where males and females live together year-round, male amicable behavior could be the best male mating strategy, thus leading to a reduction in circulating testosterone levels.
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Affiliation(s)
- Loreto A Correa
- Escuela de Medicina Veterinaria, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Camino la Pirámide 5750, Huechuraba, Santiago, Chile.
| | - Antonia Aspillaga-Cid
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Carolyn M Bauer
- Department of Biology, Swarthmore College, Swarthmore, PA, USA
| | - Danna Silva-Álvarez
- Escuela de Medicina Veterinaria, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Camino la Pirámide 5750, Huechuraba, Santiago, Chile
| | - Cecilia León
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Ramírez-Estrada
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mauricio Soto-Gamboa
- Laboratorio de Ecología Conductual y Conservación, Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Loren D Hayes
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA
| | - Luis A Ebensperger
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Correa LA, Aspillaga-Cid A, León C, Bauer CM, Ramírez-Estrada J, Hayes LD, Soto-Gamboa M, Ebensperger LA. Social environment and anogenital distance length phenotype interact to explain testosterone levels in a communally rearing rodent: Part 2: The female side. Horm Behav 2024; 160:105486. [PMID: 38295731 DOI: 10.1016/j.yhbeh.2024.105486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 01/09/2024] [Accepted: 01/12/2024] [Indexed: 03/26/2024]
Abstract
Testosterone is known as a "male" hormone; however, females also synthetize testosterone, which influences female sexual and aggressive behavior. In female vertebrates, as in males, testosterone levels can vary seasonally. However, female testosterone levels may also be related with female anogenital distance (AGD) length phenotype (a proxy of prenatal androgen exposure), and the social group environment. We used data from a long-term rodent study (2009-2019) in a natural population of degus (Octodon degus) to examine the potential associations between female serum testosterone levels, season, female AGD phenotype, and social group composition. We quantified female serum testosterone levels during the mating and offspring rearing seasons, and we determined the number of females and males in social groups, as well the composition of groups, in terms of the AGD of the female and male group mates. Our results indicate that female testosterone levels vary with season, being highest during the offspring rearing season. Additionally, female testosterone levels were associated with the number of male group-members and the AGD of male group-members but were not associated with female social environment and focal female AGD phenotype. Together, our results suggest that female testosterone levels are sensitive to intersexual interactions. Our results also reveal that female and male testosterone levels do not differ between the sexes, a finding previously reported only in rock hyraxes. We discuss how the complex social system of degus could be driving this physiological similarity between the sexes.
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Affiliation(s)
- Loreto A Correa
- Escuela de Medicina Veterinaria, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Camino la Pirámide 5750, Huechuraba, Santiago, Chile.
| | - Antonia Aspillaga-Cid
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Cecilia León
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Carolyn M Bauer
- Department of Biology, Swarthmore College, Swarthmore, PA 19081, USA
| | - Juan Ramírez-Estrada
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Loren D Hayes
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA
| | - Mauricio Soto-Gamboa
- Laboratorio de Ecología Conductual y Conservación, Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
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Bravo A, Fernández-García L, Ibarra-Karmy R, Mardones GA, Mercado L, Bustos FJ, Gifford RJ, Arriagada G. Antiviral Activity of an Endogenous Parvoviral Element. Viruses 2023; 15:1420. [PMID: 37515112 PMCID: PMC10384997 DOI: 10.3390/v15071420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
Endogenous viral elements (EVEs) are genomic DNA sequences derived from viruses. Some EVEs have open reading frames (ORFs) that can express proteins with physiological roles in their host. Furthermore, some EVEs exhibit a protective role against exogenous viral infection in their host. Endogenous parvoviral elements (EPVs) are highly represented in mammalian genomes, and although some of them contain ORFs, their function is unknown. We have shown that the locus EPV-Dependo.43-ODegus, an EPV with an intact ORF, is transcribed in Octodon degus (degu). Here we examine the antiviral activity of the protein encoded in this EPV, named DeRep. DeRep was produced in bacteria and used to generate antibodies that recognize DeRep in western blots of degu tissue. To test if DeRep could protect against exogenous parvovirus, we challenged cells with the minute virus of mice (MVM), a model autonomous parvovirus. We observed that MVM protein expression, DNA damage induced by replication, viral DNA, and cytopathic effects are reduced when DeRep is expressed in cells. The results of this study demonstrate that DeRep is expressed in degu and can inhibit parvovirus replication. This is the first time that an EPV has been shown to have antiviral activity against an exogenous virus.
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Affiliation(s)
- Angelica Bravo
- Instituto de Ciencias Biomedicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370071, Chile
| | - Leandro Fernández-García
- Instituto de Ciencias Biomedicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370071, Chile
| | - Rodrigo Ibarra-Karmy
- Instituto de Ciencias Biomedicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370071, Chile
| | - Gonzalo A Mardones
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia 5110466, Chile
| | - Luis Mercado
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile
| | - Fernando J Bustos
- Instituto de Ciencias Biomedicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370071, Chile
| | - Robert J Gifford
- Centre for Virus Research, MRC-University of Glasgow, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK
| | - Gloria Arriagada
- Instituto de Ciencias Biomedicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370071, Chile
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Pereira M, Smiley KO, Lonstein JS. Parental Behavior in Rodents. ADVANCES IN NEUROBIOLOGY 2022; 27:1-53. [PMID: 36169811 DOI: 10.1007/978-3-030-97762-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Members of the order Rodentia are among the best-studied mammals for understanding the patterns, outcomes, and biological determinants of maternal and paternal caregiving. This research has provided a wealth of information but has historically focused on just a few rodents, mostly members of the two Myomorpha families that easily breed and can be studied within a laboratory setting (including laboratory rats, mice, hamsters, voles, gerbils). It is unclear how well this small collection of animals represents the over 2000 species of extant rodents. This chapter provides an overview of the hormonal and neurobiological systems involved in parental care in rodents, with a purposeful eye on providing information known or could be gleaned about parenting in various less-traditional members of Rodentia. We conclude from this analysis that the few commonly studied rodents are not necessarily even representative of the highly diverse members of Myomorpha, let alone other rodent suborders, and that additional laboratory and field studies of members of this order more broadly would surely provide invaluable information toward revealing a more representative picture of the rich diversity in rodent parenting.
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Affiliation(s)
- Mariana Pereira
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA
| | - Kristina O Smiley
- Centre for Neuroendocrinology & Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Joseph S Lonstein
- Department of Psychology & Neuroscience Program, Michigan State University, East Lansing, MI, USA.
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Correa LA, León C, Ramírez-Estrada J, Ly-Prieto Á, Abades S, Hayes LD, Soto-Gamboa M, Ebensperger LA. One for all and all for one: phenotype assortment and reproductive success in masculinized females. Behav Ecol 2021. [DOI: 10.1093/beheco/arab093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Abstract
Homophily by morphological and behavioral traits has been described in several species of vertebrates, but its functional consequences remain poorly studied. Homophily by plurally breeding females may improve direct fitness by enhancing reproductive success. Female mammals may exhibit phenotypical masculinization due to exposure to androgens during early development, a condition that is associated with maternal performance during subsequent breeding. Our goal was to assess whether female composition (in terms of masculinization) of plurally breeding groups influences female fitness in a natural population of degus (Octodon degus). We assessed if plurally breeding female degus assort themselves by anogenital distance (AGD), an accurate measure of masculinization level. We also quantified if homophily by AGD phenotype affects female reproductive success and the reproductive output of the group. Plurally breeding groups typically included similarly masculinized (i.e., long AGD) females or similarly feminized (short AGD) females, indicating a strong degree of homophily. Females weaned more offspring in plurally breeding groups with more masculinized females. Additionally, standardized variance in the number of offspring weaned decreased in plurally breeding groups with mostly masculinized females, indicating greater reproductive equality in these groups. We conclude that female degus organize into homophilic social groups of similar AGD, and that social groups of masculinized females exhibit a higher reproductive success.
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Affiliation(s)
- Loreto A Correa
- Escuela de Medicina Veterinaria, Facultad de Ciencias, Universidad Mayor, Camino la Pirámide, Huechuraba, Santiago, Chile
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
| | - Cecilia León
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
| | - Juan Ramírez-Estrada
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
| | - Álvaro Ly-Prieto
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
| | - Sebastián Abades
- GEMA Center for Genomics, Ecology & Environment, Faculty of Interdisciplinary Studies, Universidad Mayor, Camino La Pirámide, Huechuraba, Santiago, Chile
| | - Loren D Hayes
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN, USA
| | - Mauricio Soto-Gamboa
- Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Casilla, Isla Teja s/n, Valdivia, Chile
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
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