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Orr TJ, Lukitsch T, Eiting TP, Brennan PLR. Testing Morphological Relationships Between Female and Male Copulatory Structures in Bats. Integr Comp Biol 2022; 62:icac040. [PMID: 35661885 DOI: 10.1093/icb/icac040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The lower reproductive tract of female mammals has several competing functions including mating, tract health maintenance, and parturition. Diverse vaginal anatomy suggests interactions between natural and sexual selection, yet despite its importance, female copulatory morphology remains under-studied. We undertook a comparative study across the species-rich mammalian order Chiroptera (bats) with a focus on the suborder Yangochiroptera (Vespertilioniformes) to examine how female vaginal features may have coevolved with male penis morphology to minimize mechanical damage to their tissues during copulation. The penis morphology is diverse, presenting great potential for post-copulatory sexual selection and coevolution with the female morphology, but vaginas have not been carefully examined. Here we test the hypotheses that vaginal thickness and collagen density have coevolved with features of the male penis including the presence of spines and a baculum. We present histological data from females of 24 species from 7 families of bats, and corresponding data on male penis anatomy. We also examine the role of phylogenetic history in the morphological patterns we observe. We found evidence that female vaginal thickness has coevolved with the presence of penile spines, but not with baculum presence or width. Collagen density did not appear to covary with male penile features. Our findings highlight the importance of considering interactions between the sexes in influencing functional reproductive structures and examine how these structures have been under selection in bats.
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Affiliation(s)
- Teri J Orr
- New Mexico State University, Department of Biology, Las Cruces, NM 88003
| | - Theresa Lukitsch
- New Mexico State University, Department of Biology, Las Cruces, NM 88003
| | - Thomas P Eiting
- Department of Neurobiology, University of Utah, Salt Lake City, UT 84112
| | - Patricia L R Brennan
- Department of Biological Sciences, Mount Holyoke College, South Hadley, MA 01075
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Nabi G, Hao Y, Liu X, Sun Y, Wang Y, Jiang C, Li J, Wu Y, Li D. Hypothalamic-Pituitary-Thyroid Axis Crosstalk With the Hypothalamic-Pituitary-Gonadal Axis and Metabolic Regulation in the Eurasian Tree Sparrow During Mating and Non-mating Periods. Front Endocrinol (Lausanne) 2020; 11:303. [PMID: 32547486 PMCID: PMC7272604 DOI: 10.3389/fendo.2020.00303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/21/2020] [Indexed: 12/13/2022] Open
Abstract
Reproduction is an energetically costly phenomenon. Therefore, to optimize reproductive success, male birds invest enough energetic resources for maintaining well-developed testes. The hypothalamic-pituitary-thyroid (HPT) axis in birds can crosstalk with the hypothalamic-pituitary-gonadal (HPG) axis, thus orchestrating both the reproduction and metabolism. However, until now, how the free-living birds timely optimize both the energy metabolism and reproduction via HPT-axis is not understood. To uncover this physiological mechanism, we investigated the relationships among body mass, testis size, plasma hormones including thyroid-stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3), metabolites including glucose (Glu), triglyceride (TG), total cholesterol (TC), uric acid (UA), diencephalon mRNA expressions of type 2 (Dio2) and 3 (Dio3) iodothyronine deiodinase enzymes, thyrotropin-releasing hormone (TRH), thyroid-stimulating hormone (TSH), gonadotropin-releasing hormone I (GnRH-I), and gonadotropin-inhibitory hormone (GnIH) in a male Eurasian tree sparrow (ETS, Passer montanus). We found significantly larger testis size; elevated diencephalon Dio2 and TRH mRNA expressions, plasma T3, and UA levels; and significantly lowered Glu, TG, and TC levels during mating relative to the non-mating stages in male ETSs. However, Dio3, TSH, GnRH-I, and GnIH mRNA expression did not vary with the stage. Furthermore, life-history stage dependent variation in plasma T3 had both direct effects on the available energy substrates and indirect effects on body mass and testis size, indicating a complex regulation of metabolic pathways through the HPT- and HPG-axes. The identified differences and relationships in mRNA expression, plasma T3 and metabolites, and testis size in male ETSs contribute to our understanding how free-living birds adjust their molecular, endocrinal, and biochemical features to orchestrate their reproductive physiology and metabolism for the maintenance of well-developed testes.
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Affiliation(s)
- Ghulam Nabi
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Yinchao Hao
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Functional Laboratory, Experimental Center for Teaching, Hebei Medical University, Shijiazhuang, China
| | - Xuelu Liu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Yanfeng Sun
- Ocean College, Hebei Agricultural University, Qinhuangdao, China
| | - Yang Wang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Chuan Jiang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Juyong Li
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Yuefeng Wu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Dongming Li
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- *Correspondence: Dongming Li
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Abstract
Objectives: To investigate the prevalence and severity of varicocele in adult population over the age of 40. We also measured testicular size, consistency, and total testosterone levels with an aim to observe the effect of varicocele on testis as men age. Methods: Two hundred twenty-four patients with varicocele, 241 patients without varicocele who admitted to our clinic were enrolled in the study. We stratified participants by four age groups (40-49, 50-59, 60-69, >70 yr). Patients were grouped according to varicocele grade and laterality. The morning testosterone level was drawn. The subgroups were compared with each other. Results: Overall, varicocele prevalence was 48%. Of the patients, 104 had unilateral, 120 had bilateral varicocele. Of the patients with varicocele, 62 (13.30%) were found as grade 3, 99 (21.10%) were grade 2, and 63 (13.60%) were grade 1. The percentages of smaller testes in grade 1, grade 2, and grade 3 varicocele group were 20.60, 79.80, and 88.70 and a significant association was detected. Age stratification of the data revealed the smaller and soft testis prevalence as well as higher grade varicocele prevalance increased in older age groups. Conclusions: Varicocele presence is associated with lower testicular size, softer testicular consistency, and lower testosterone levels, especially in older patients with bilateral and high-grade varicocele.
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Affiliation(s)
- Huseyin Besiroglu
- a Department of Urology , Catalca Ilyas Cokay State Hospital , Istanbul , Turkey
| | - Alper Otunctemur
- b Department of Urology , Okmeydani Training and Research Hospital , Istanbul , Turkey
| | - Murat Dursun
- c Department of Urology , Malatya Training and Research Hospital , Istanbul , Turkey
| | - Emin Ozbek
- d Department of Urology, Cerrahpasa Medicine Faculty , Istanbul , Turkey
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Simmons LW, Lüpold S, Fitzpatrick JL. Evolutionary Trade-Off between Secondary Sexual Traits and Ejaculates. Trends Ecol Evol 2017; 32:964-976. [PMID: 29050795 DOI: 10.1016/j.tree.2017.09.011] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 09/21/2017] [Accepted: 09/22/2017] [Indexed: 12/29/2022]
Abstract
Recent theoretical models predict that the evolutionary diversification of the weapons and ornaments of pre-mating sexual selection should be influenced by trade-offs with male expenditure on ejaculates. However, the patterns of association between secondary sexual traits and ejaculate expenditure are frequently inconsistent in their support of this prediction. We show why consideration of additional life-history, ecological, and mating-system variables is crucial for the interpretation of associations between secondary sexual traits and ejaculate production. Incorporation of these 'missing variables' provides evidence that interactions between pre- and post-mating sexual selection can underlie broad patterns of diversification in male weapons and ornaments. We call for more experimental and genetic approaches to uncover trade-offs, as well as for studies that consider the costs of mate-searching.
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Affiliation(s)
- Leigh W Simmons
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia.
| | - Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - John L Fitzpatrick
- Department of Zoology and Ethology, Stockholm University, Svante Arrhenius väg 18B, SE-10691 Stockholm, Sweden
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Pick JL, Hutter P, Tschirren B. Divergent artificial selection for female reproductive investment has a sexually concordant effect on male reproductive success. Evol Lett 2017; 1:222-228. [PMID: 30283651 PMCID: PMC6121851 DOI: 10.1002/evl3.21] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/31/2017] [Accepted: 08/03/2017] [Indexed: 01/08/2023] Open
Abstract
Depending on the genetic architecture of male and female fitness, sex-specific selection can have negative, positive, or neutral consequences for the opposite sex. Theory predicts that conflict between male and female function may drive the breakdown of intrasexual genetic correlations, allowing sexual dimorphism in sexually antagonistic traits. Reproductive traits are the epitome of this, showing highly differentiated proximate functions between the sexes. Here we use divergent artificial selection lines for female reproductive investment to test how female-specific selection on a sex-limited trait affects male reproductive success in a precocial bird, the Japanese quail (Coturnix japonica). We demonstrate that selection for increased egg investment in females positively affects male reproductive success both in competitive and non-competitive mating situations. This increased reproductive success was linked to a relatively larger left testis in males originating from lines selected for high female reproductive investment. Given that female quail have functional gonads only on their left side, this correlated response indicates that selection has acted on the shared developmental basis of male and female gonads. Our study thereby provides evidence for a positive genetic correlation between key reproductive traits in males and females despite a high degree of sexual dimorphism, and suggests that, in this system, selection on reproductive function is sexually concordant.
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Affiliation(s)
- Joel L. Pick
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland
- Department of Animal and Plant SciencesUniversity of SheffieldWestern BankSheffield S10 2TNUnited Kingdom
- School of Biological, Earth and Environmental SciencesUniversity of New South WalesRandwick, NSW 2052SydneyAustralia
| | - Pascale Hutter
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland
| | - Barbara Tschirren
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland
- Centre for Ecology and ConservationUniversity of ExeterPenryn TR10 9FEUnited Kingdom
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Giraudeau M, Ziegler AK, Tschirren B. Long-term effect of yolk carotenoid levels on testis size in a precocial bird. Biol Lett 2017; 12:rsbl.2016.0008. [PMID: 27122006 DOI: 10.1098/rsbl.2016.0008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/05/2016] [Indexed: 11/12/2022] Open
Abstract
Conditions experienced during prenatal development can have long-lasting organizational effects on offspring. Maternal carotenoids deposited in the eggs of birds and other oviparous species play an important role during fast embryonic growth and chick development through their antioxidant properties. However, the long-term consequences of variation in maternal carotenoid transfer for the offspring have seldom been considered. Since plasma carotenoid levels at adulthood are known to influence testis size and yolk carotenoid levels influence the ability to extract carotenoids later in life, we hypothesized that maternally transmitted carotenoids might influence gonad size at adulthood. Here, we showed that male Japanese quail (Coturnix japonica) originating from a carotenoid-enriched egg had smaller testes than control individuals at adulthood. This result shows that yolk carotenoids have long-term organizational effects. In addition, given that carotenoid intake at sexual maturity increases sperm quality and that a decreased testis size is associated with a lower sperm production, we propose that carotenoid exposure during embryo development might influence a trade-off between ejaculate size and sperm quality.
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Affiliation(s)
- Mathieu Giraudeau
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
| | - Ann-Kathrin Ziegler
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
| | - Barbara Tschirren
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
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Kahrl AF, Cox CL, Cox RM. Correlated evolution between targets of pre- and postcopulatory sexual selection across squamate reptiles. Ecol Evol 2016; 6:6452-6459. [PMID: 27777721 PMCID: PMC5058519 DOI: 10.1002/ece3.2344] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 06/28/2016] [Accepted: 06/30/2016] [Indexed: 11/25/2022] Open
Abstract
Sexual selection reflects the joint contributions of precopulatory selection, which arises from variance in mating success, and postcopulatory selection, which arises from variance in fertilization success. The relative importance of each episode of selection is variable among species, and comparative evidence suggests that traits targeted by precopulatory selection often covary in expression with those targeted by postcopulatory selection when assessed across species, although the strength and direction of this association varies considerably among taxa. We tested for correlated evolution between targets of pre‐ and postcopulatory selection using data on sexual size dimorphism (SSD) and testis size from 151 species of squamate reptiles (120 lizards, 31 snakes). In squamates, male–male competition for mating opportunities often favors large body size, such that the degree of male‐biased SSD is associated with the intensity of precopulatory selection. Likewise, competition for fertilization often favors increased sperm production, such that testis size (relative to body size) is associated with the intensity of postcopulatory selection. Using both conventional and phylogenetically based analyses, we show that testis size consistently decreases as the degree of male‐biased SSD increases across lizards and snakes. This evolutionary pattern suggests that strong precopulatory selection may often constrain the opportunity for postcopulatory selection and that the relative importance of each selective episode may determine the optimal resolution of energy allocation trade‐offs between traits subject to each form of sexual selection.
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Affiliation(s)
- Ariel F Kahrl
- Department of Biology University of Virginia Charlottesville Virginia 22904
| | - Christian L Cox
- Department of Biology Georgia Southern University Statesboro Georgia 30460
| | - Robert M Cox
- Department of Biology University of Virginia Charlottesville Virginia 22904
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Shiel BP, Sherman CDH, Elgar MA, Johnson TL, Symonds MRE. Investment in sensory structures, testis size, and wing coloration in males of a diurnal moth species: trade-offs or correlated growth? Ecol Evol 2015; 5:1601-8. [PMID: 25937904 PMCID: PMC4409409 DOI: 10.1002/ece3.1459] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 02/10/2015] [Accepted: 02/16/2015] [Indexed: 11/17/2022] Open
Abstract
For dioecious animals, reproductive success typically involves an exchange between the sexes of signals that provide information about mate location and quality. Typically, the elaborate, secondary sexual ornaments of males signal their quality, while females may signal their location and receptivity. In theory, the receptor structures that receive the latter signals may also become elaborate or enlarged in a way that ultimately functions to enhance mating success through improved mate location. The large, elaborate antennae of many male moths are one such sensory structure, and eye size may also be important in diurnal moths. Investment in these traits may be costly, resulting in trade-offs among different traits associated with mate location. For polyandrous species, such trade-offs may also include traits associated with paternity success, such as larger testes. Conversely, we would not expect this to be the case for monandrous species, where sperm competition is unlikely. We investigated these ideas by evaluating the relationship between investment in sensory structures (antennae, eye), testis, and a putative warning signal (orange hindwing patch) in field-caught males of the monandrous diurnal painted apple moth Teia anartoides (Lepidoptera: Lymantriidae) in southeastern Australia. As predicted for a monandrous species, we found no evidence that male moths with larger sensory structures had reduced investment in testis size. However, contrary to expectation, investment in sensory structures was correlated: males with relatively larger antennae also had relatively larger eyes. Intriguingly, also, the size of male orange hindwing patches was positively correlated with testis size.
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Affiliation(s)
- Brett P Shiel
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University 221 Burwood Highway, Burwood, Melbourne, Victoria, 3125, Australia
| | - Craig D H Sherman
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University Pigdons Road, Waurn Ponds, Victoria, 3217, Australia
| | - Mark A Elgar
- School of BioSciences, University of Melbourne Melbourne, Victoria, 3010, Australia
| | - Tamara L Johnson
- School of BioSciences, University of Melbourne Melbourne, Victoria, 3010, Australia
| | - Matthew R E Symonds
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University 221 Burwood Highway, Burwood, Melbourne, Victoria, 3125, Australia
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