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Duerwachter MA, Lewis EL, French SS, Husak JF. Sex-specific effects of immune challenges on green anole lizard metabolism. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:264-271. [PMID: 38213098 DOI: 10.1002/jez.2779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 01/13/2024]
Abstract
Immune responses can increase survival, but they can also incur a variety of costs that may lead to phenotypic trade-offs. The nature of trade-offs between immune activity and other components of the phenotype can vary and depend on the type and magnitude of immune challenge, as well as the energetic costs of simultaneously expressing other traits. There may also be sex-specific differences in both immune activity and trade-offs, particularly with regard to energy expenditure that might differ between males and females during the breeding season. Females are generally expected to invest less in nonspecific immune responses compared to males due to differences in the allocation of resources to reproduction, which may lead to sex differences in the metabolic costs of immunity. We tested for sex-specific differences in metabolic costs of different types of immune challenges in Anolis carolinensis lizards, including lipopolysaccharide (LPS) injection and wounding. We also tested for differences in immune prioritization by measuring bacterial killing ability (BKA). We predicted males would show a greater increase in metabolism after immune challenges, with combined immune challenges eliciting the greatest response. Furthermore, we predicted that metabolic costs would result in decreased BKA. LPS injection increased the resting metabolic rate (RMR) of males but not females. Wounding did not affect RMR of either sex. However, there was an inverse relationship between BKA and wound healing in LPS-injected lizards, suggesting dynamic tradeoffs among metabolism and components of the immune system.
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Affiliation(s)
| | - Erin L Lewis
- Department of Biology, Utah State University, Logan, Utah, USA
| | | | - Jerry F Husak
- Department of Biology, University of St. Thomas, St. Paul, Minnesota, USA
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2
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Shankey NT, Cohen RE. Neural control of reproduction in reptiles. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:307-321. [PMID: 38247297 DOI: 10.1002/jez.2783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 01/03/2024] [Accepted: 01/04/2024] [Indexed: 01/23/2024]
Abstract
Reptiles display considerable diversity in reproductive behavior, making them great models to study the neuroendocrine control of reproductive behavior. Many reptile species are seasonally breeding, such that they become reproductively active during their breeding season and regress to a nonreproductive state during their nonbreeding season, with this transition often prompted by environmental cues. In this review, we will focus on summarizing the neural and neuroendocrine mechanisms controlling reproductive behavior. Three major areas of the brain are involved in reproductive behavior: the preoptic area (POA), amygdala, and ventromedial hypothalamus (VMH). The POA and VMH are sexually dimorphic areas, regulating behaviors in males and females respectively, and all three areas display seasonal plasticity. Lesions to these areas disrupt the onset and maintenance of reproductive behaviors, but the exact roles of these regions vary between sexes and species. Different hormones influence these regions to elicit seasonal transitions. Circulating testosterone (T) and estradiol (E2) peak during the breeding season and their influence on reproduction is well-documented across vertebrates. The conversion of T into E2 and 5α-dihydrotestosterone can also affect behavior. Melatonin and corticosterone have generally inhibitory effects on reproductive behavior, while serotonin and other neurohormones seem to stimulate it. In general, there is relatively little information on the neuroendocrine control of reproduction in reptiles compared to other vertebrate groups. This review highlights areas that should be considered for future areas of research.
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Affiliation(s)
- Nicholas T Shankey
- Department of Biological Sciences, Minnesota State University, Mankato, Mankato, Minnesota, USA
| | - Rachel E Cohen
- Department of Biological Sciences, Minnesota State University, Mankato, Mankato, Minnesota, USA
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3
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Yamagishi G, Miyagawa S. Neuroendocrinology of Reproduction and Social Behaviors in Reptiles: Advances Made in the Last Decade. Zoolog Sci 2024; 41:87-96. [PMID: 38587521 DOI: 10.2108/zs230060] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/03/2023] [Indexed: 04/09/2024]
Abstract
Among amniotes, reptiles are ectothermic and are clearly distinguished from mammals and birds. Reptiles show great diversity not only in species numbers, but also in ecological and physiological features. Although their physiological diversity is an interesting research topic, less effort has been made compared to that for mammals and birds, in part due to lack of established experimental models and techniques. However, progress, especially in the field of neuroendocrinology, has been steadily made. With this process, basic data on selected reptilian species have been collected. This review article presents the progress made in the last decade, which includes 1) behavioral regulation by sex steroid hormones, 2) regulation of seasonal reproduction by melatonin and GnRH, and 3) regulation of social interaction by arginine vasotocin. Through these research topics, we provide insights into the physiology of reptiles and the latest findings in the field of amniote neuroendocrinology.
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Affiliation(s)
- Genki Yamagishi
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Katsushika-ku, Tokyo 125-8585, Japan,
| | - Shinichi Miyagawa
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Katsushika-ku, Tokyo 125-8585, Japan,
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4
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Marks JR, Sorlin M, Lailvaux SP. The maternal energetic environment affects both egg and offspring phenotypes in green anole lizards ( Anolis carolinensis). Ecol Evol 2023; 13:e9656. [PMID: 36628150 PMCID: PMC9822813 DOI: 10.1002/ece3.9656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 01/08/2023] Open
Abstract
Animals exist in dynamic environments that may affect both their own fitness and that of their offspring. Maternal effects might allow mothers to prepare their offspring for the environment in which they will be born via several mechanisms, not all of which are well understood. Resource scarcity and forced resource allocation are two scenarios that could affect maternal investment by altering the amount and type of resources available for investment in offspring, albeit in potentially different ways. We tested the hypothesis that maternal dietary restriction and sprint training have different consequences for the offspring phenotype in an oviparous lizard (Anolis carolinensis). To do this, we collected and reared eggs from adult diet-manipulated females (low-diet [LD] or high-diet [HD]) and sprint-trained females (sprint trained [ST] or untrained [UT]) and measured both egg characteristics and hatchling morphology. ST and LD mothers laid both the fewest and heaviest eggs, and ST, UT, and LD eggs also had significantly longer incubation periods than the HD group. Hatchlings from the diet experiment (LD and HD offspring) were the heaviest overall. Furthermore, both body mass of the mother at oviposition and change in maternal body mass over the course of the experiment had significant and sometimes different effects on egg and offspring phenotypes, highlighting the importance of maternal energetic state to the allocation of maternal resources.
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Affiliation(s)
- Jamie R. Marks
- Department of BiologyUniversity of New OrleansNew OrleansLouisianaUSA
| | - Mahaut Sorlin
- Department of BiologyUniversity of New OrleansNew OrleansLouisianaUSA
| | - Simon P. Lailvaux
- Department of BiologyUniversity of New OrleansNew OrleansLouisianaUSA
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5
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Taylor LA, Thawley CJ, Pertuit OR, Dennis AJ, Carson IR, Tang C, Johnson MA. Artificial light at night alters diurnal and nocturnal behavior and physiology in green anole lizards. Physiol Behav 2022; 257:113992. [DOI: 10.1016/j.physbeh.2022.113992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/23/2022] [Accepted: 10/07/2022] [Indexed: 11/06/2022]
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6
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Card DC, Van Camp AG, Santonastaso T, Jensen-Seaman MI, Anthony NM, Edwards SV. Structure and evolution of the squamate major histocompatibility complex as revealed by two Anolis lizard genomes. Front Genet 2022; 13:979746. [PMID: 36425073 PMCID: PMC9679377 DOI: 10.3389/fgene.2022.979746] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/20/2022] [Indexed: 11/10/2022] Open
Abstract
The major histocompatibility complex (MHC) is an important genomic region for adaptive immunity and has long been studied in ecological and evolutionary contexts, such as disease resistance and mate and kin selection. The MHC has been investigated extensively in mammals and birds but far less so in squamate reptiles, the third major radiation of amniotes. We localized the core MHC genomic region in two squamate species, the green anole (Anolis carolinensis) and brown anole (A. sagrei), and provide the first detailed characterization of the squamate MHC, including the presence and ordering of known MHC genes in these species and comparative assessments of genomic structure and composition in MHC regions. We find that the Anolis MHC, located on chromosome 2 in both species, contains homologs of many previously-identified mammalian MHC genes in a single core MHC region. The repetitive element composition in anole MHC regions was similar to those observed in mammals but had important distinctions, such as higher proportions of DNA transposons. Moreover, longer introns and intergenic regions result in a much larger squamate MHC region (11.7 Mb and 24.6 Mb in the green and brown anole, respectively). Evolutionary analyses of MHC homologs of anoles and other representative amniotes uncovered generally monophyletic relationships between species-specific homologs and a loss of the peptide-binding domain exon 2 in one of two mhc2β gene homologs of each anole species. Signals of diversifying selection in each anole species was evident across codons of mhc1, many of which appear functionally relevant given known structures of this protein from the green anole, chicken, and human. Altogether, our investigation fills a major gap in understanding of amniote MHC diversity and evolution and provides an important foundation for future squamate-specific or vertebrate-wide investigations of the MHC.
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Affiliation(s)
- Daren C. Card
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
- Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States
- *Correspondence: Daren C. Card,
| | - Andrew G. Van Camp
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
- Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States
| | - Trenten Santonastaso
- Department of Biological Sciences, University of New Orleans, New Orleans, LA, United States
| | | | - Nicola M. Anthony
- Department of Biological Sciences, University of New Orleans, New Orleans, LA, United States
| | - Scott V. Edwards
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
- Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States
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7
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Kabelik D, Julien AR, Waddell BR, Batschelett MA, O'Connell LA. Aggressive but not reproductive boldness in male green anole lizards correlates with baseline vasopressin activity. Horm Behav 2022; 140:105109. [PMID: 35066329 DOI: 10.1016/j.yhbeh.2022.105109] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 12/20/2021] [Accepted: 01/04/2022] [Indexed: 11/18/2022]
Abstract
Across species, individuals within a population differ in their level of boldness in social encounters with conspecifics. This boldness phenotype is often stable across both time and social context (e.g., reproductive versus agonistic encounters). Various neural and hormonal mechanisms have been suggested as underlying these stable phenotypic differences, which are often also described as syndromes, personalities, and coping styles. Most studies examining the neuroendocrine mechanisms associated with boldness examine subjects after they have engaged in a social interaction, whereas baseline neural activity that may predispose behavioral variation is understudied. The present study tests the hypotheses that physical characteristics, steroid hormone levels, and baseline variation in Ile3-vasopressin (VP, a.k.a., Arg8-vasotocin) signaling predispose boldness during social encounters. Boldness in agonistic and reproductive contexts was extensively quantified in male green anole lizards (Anolis carolinensis), an established research organism for social behavior research that provides a crucial comparison group to investigations of birds and mammals. We found high stability of boldness across time, and between agonistic and reproductive contexts. Next, immunofluorescence was used to colocalize VP neurons with phosphorylated ribosomal protein S6 (pS6), a proxy marker of neural activity. Vasopressin-pS6 colocalization within the paraventricular and supraoptic nuclei of the hypothalamus was inversely correlated with boldness of aggressive behaviors, but not of reproductive behaviors. Our findings suggest that baseline vasopressin release, rather than solely context-dependent release, plays a role in predisposing individuals toward stable levels of displayed aggression toward conspecifics by inhibiting behavioral output in these contexts.
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Affiliation(s)
- David Kabelik
- Department of Biology & Program in Neuroscience, Rhodes College, Memphis, TN 38112, USA.
| | - Allison R Julien
- Department of Biology & Program in Neuroscience, Rhodes College, Memphis, TN 38112, USA
| | - Brandon R Waddell
- Department of Biology & Program in Neuroscience, Rhodes College, Memphis, TN 38112, USA
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8
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Campos SM, Erley A, Ashraf Z, Wilczynski W. Signaler's Vasotocin Alters the Relationship between the Responder's Forebrain Catecholamines and Communication Behavior in Lizards (Anolis carolinensis). BRAIN, BEHAVIOR AND EVOLUTION 2022; 97:184-196. [PMID: 35320812 DOI: 10.1159/000524217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
Dynamic fluctuations in the distribution of catecholamines across the brain modulate the responsiveness of vertebrates to social stimuli. Previous work demonstrates that green anoles (Anolis carolinensis) increase chemosensory behavior in response to males treated with exogenous arginine vasotocin (AVT), but the neurochemical mechanisms underlying this behavioral shift remains unclear. Since central catecholamine systems, including dopamine, rapidly activate in response to social stimuli, we tested whether exogenous AVT in signalers (stimulus animals) impacts catecholamine concentrations in the forebrain (where olfactory and visual information are integrated and processed) of untreated lizard responders. We also tested whether AVT influences the relationship between forebrain catecholamine concentrations and communication behavior in untreated receivers. We measured global catecholamine (dopamine = DA, epinephrine = Epi, and norepinephrine = NE) concentrations in the forebrain of untreated responders using high-performance liquid chromatography-mass spectrometry following either a 30-min social interaction with a stimulus male or a period of social isolation. Stimulus males were injected with exogenous AVT or vehicle saline (SAL). We found that global DA, but not Epi or NE, concentrations were elevated in lizards responding to SAL-males relative to isolated lizards. Lizards interacting with AVT-males had DA, Epi and NE concentrations that were not significantly different from SAL or isolated groups. For behavior, we found a significant effect of social treatment (AVT vs. SAL) on the relationships between (1) DA concentrations and the motivation to perform a chemical display (latency to tongue flick) and (2) Epi concentrations and time spent displaying mostly green body coloration. We also found a significant negative correlation between DA concentrations and the latency to perform a visual display but found no effect of social treatment on this relationship. These data suggest that catecholamine concentrations in the forebrain of untreated responders are associated with chemical and visual communication in lizards and that signaler AVT alters this relationship for some, but not all, aspects of social communication.
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Affiliation(s)
- Stephanie M Campos
- Biology, Swarthmore College, Swarthmore, Pennsylvania, USA
- Neuroscience Institute and Center for Behavioral Neuroscience, Georgia State University, Atlanta, Georgia, USA
| | | | - Zoha Ashraf
- Biology, Swarthmore College, Swarthmore, Pennsylvania, USA
| | - Walter Wilczynski
- Neuroscience Institute and Center for Behavioral Neuroscience, Georgia State University, Atlanta, Georgia, USA
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9
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Tao CY, Harley JZ, Spencer SL, Cohen RE. Characterizing seasonal transitions: Breeding-like morphology and behavior during the late non-breeding season in green anole lizards. Horm Behav 2022; 139:105106. [PMID: 34995849 DOI: 10.1016/j.yhbeh.2021.105106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 12/03/2021] [Accepted: 12/22/2021] [Indexed: 11/19/2022]
Abstract
Seasonally breeding animals, such as green anole lizards (Anolis carolinensis), allow for the examination of the control of reproduction during different reproductive states. During the breeding season, the gonads are large and reproductively active. Following the breeding season, gonads regress and become less active, and the lizards enter a refractory period where breeding is inhibited. After this stage, a post-refractory period occurs during which the lizards are still in a non-breeding state, but environmental changes can trigger the onset of breeding. However, it is unclear what causes these changes in reproductive state and we hypothesized that this may be due to alterations in gonadotropin-releasing hormone (GnRH) signaling. The present study aimed to identify morphological and behavioral differences in GnRH- and saline-injected refractory and post-refractory male anoles when housed under the same non-breeding environmental conditions. We found that post-refractory anoles had increased testicular weight, recrudescence, sperm presence, and reproductive behavior, with no impact of GnRH injection. Renal sex segment size and steroidogenic acute regulatory protein (StAR) mRNA levels did not differ among groups, indicating that testosterone levels likely had not increased in post-refractory lizards. Post-refractory anoles in this study were beginning to transition towards a breeding state without exposure to changing environmental conditions, and GnRH was not necessary for these changes. These data reveal a complex interaction between the activation of breeding, changing environmental conditions, and the underlying physiology regulating reproduction in seasonally breeding lizards. Future studies are needed to further elucidate the mechanisms that regulate this relationship.
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Affiliation(s)
- Cai Y Tao
- Department of Biological Sciences, Minnesota State University, Mankato, Mankato, MN 56001-6062, USA
| | - Jada Z Harley
- Department of Biological Sciences, Minnesota State University, Mankato, Mankato, MN 56001-6062, USA
| | - Savannah L Spencer
- Department of Biological Sciences, Minnesota State University, Mankato, Mankato, MN 56001-6062, USA
| | - Rachel E Cohen
- Department of Biological Sciences, Minnesota State University, Mankato, Mankato, MN 56001-6062, USA.
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10
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Bush JM, Ellison M, Simberloff D. Impacts of an invasive species (Anolis sagrei) on social and spatial behaviours of a native congener (Anolis carolinensis). Anim Behav 2022. [DOI: 10.1016/j.anbehav.2021.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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11
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Marks JR, Beatty AE, Schwartz TS, Sorlin M, Lailvaux SP. Expression of insulin-like growth factors depends on both mass and resource availability in female green anoles (Anolis carolinensis). J Exp Biol 2021; 224:271228. [PMID: 34370031 DOI: 10.1242/jeb.242665] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 06/29/2021] [Indexed: 02/05/2023]
Abstract
The insulin and insulin-like signaling (IIS) network is an important mediator of cellular growth and metabolism in animals, and is sensitive to environmental conditions such as temperature and resource availability. The two main hormones of the IIS network, insulin-like growth factor 1 (IGF1) and insulin-like growth factor 2 (IGF2), are present in all vertebrates, yet little is known regarding the responsiveness of IGF2 in particular to external stimuli in non-mammalian animals. We manipulated diet (low or high quantity of food: low and high diet group, respectively) in adult green anole (Anolis carolinensis) females to test the effect of energetic state on hepatic gene expression of IGF1 and IGF2. The absolute expression of IGF2 in female green anoles was 100 times higher than that of IGF1 regardless of diet treatment, and IGF1 and IGF2 expression interacted with post-treatment body mass and treatment, as did the expression of the purported housekeeping genes glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and eukaryotic elongation factor 2 (EEF2). The low diet group showed a negative relationship between body mass and gene expression for all genes, whereas the relationships between body mass and gene expression in the high diet group were either absent (in the case of IGF1) or positive (for all other genes). After accounting for total change in mass, the low diet group expressed IGF2, GAPDH and EEF2 at higher levels compared with individuals in the high diet group of a similar change in mass. These results illustrate that expression of IGF1 and IGF2, and of the housekeeping genes is affected by energe-tic status in reptiles.
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Affiliation(s)
- Jamie R Marks
- Department of Biology, University of New Orleans, 2000 Lakeshore Dr., New Orleans, LA 70148, USA
| | - Abby E Beatty
- Department of Biological Sciences, Auburn University, 101 Rouse Life Sciences Bldg, Auburn, AL 36849, USA
| | - Tonia S Schwartz
- Department of Biological Sciences, Auburn University, 101 Rouse Life Sciences Bldg, Auburn, AL 36849, USA
| | - Mahaut Sorlin
- Department of Biology, University of New Orleans, 2000 Lakeshore Dr., New Orleans, LA 70148, USA
| | - Simon P Lailvaux
- Department of Biology, University of New Orleans, 2000 Lakeshore Dr., New Orleans, LA 70148, USA
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12
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Kabelik D, Julien AR, Ramirez D, O'Connell LA. Social boldness correlates with brain gene expression in male green anoles. Horm Behav 2021; 133:105007. [PMID: 34102460 PMCID: PMC8277760 DOI: 10.1016/j.yhbeh.2021.105007] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 05/01/2021] [Accepted: 05/22/2021] [Indexed: 11/27/2022]
Abstract
Within populations, some individuals tend to exhibit a bold or shy social behavior phenotype relative to the mean. The neural underpinnings of these differing phenotypes - also described as syndromes, personalities, and coping styles - is an area of ongoing investigation. Although a social decision-making network has been described across vertebrate taxa, most studies examining activity within this network do so in relation to exhibited differences in behavioral expression. Our study instead focuses on constitutive gene expression in bold and shy individuals by isolating baseline gene expression profiles that influence social boldness predisposition, rather than those reflecting the results of social interaction and behavioral execution. We performed this study on male green anole lizards (Anolis carolinensis), an established model organism for behavioral research, which provides a crucial comparison group to investigations of birds and mammals. After identifying subjects as bold or shy through repeated reproductive and agonistic behavior testing, we used RNA sequencing to compare gene expression profiles between these groups within various forebrain, midbrain, and hindbrain regions. The ventromedial hypothalamus had the largest group differences in gene expression, with bold males having increased expression of neuroendocrine and neurotransmitter receptor and calcium channel genes compared to shy males. Conversely, shy males express more integrin alpha-10 in the majority of examined regions. There were no significant group differences in physiology or hormone levels. Our results highlight the ventromedial hypothalamus as an important center of behavioral differences across individuals and provide novel candidates for investigations into the regulation of individual variation in social behavior phenotype.
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Affiliation(s)
- David Kabelik
- Department of Biology & Program in Neuroscience, Rhodes College, Memphis, TN 38112, USA.
| | - Allison R Julien
- Department of Biology & Program in Neuroscience, Rhodes College, Memphis, TN 38112, USA
| | - Dave Ramirez
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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13
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Borgmans G, Palme R, Sannen A, Vervaecke H, Van Damme R. The Effect of Long Term Captivity on Stress Levels in Anolis carolinensis Lizards. J APPL ANIM WELF SCI 2021; 24:321-330. [PMID: 33910433 DOI: 10.1080/10888705.2021.1916937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The effect of long term captivity is a factor that is important for all research utilizing wild caught animals. Despite the fact that it can be considered to be one of the most fundamental potential sources of stress in captivity, it has received a low amount of interest in recent research on lizards. Given the wide variety in ecology and life history among lizards species, it would make sense to investigate the effect of long term captivity on wild caught lizards on a broader scale. In this study we investigated the effect of long term captivity (four months) on the physiology and behavior of male and female Anolis carolinensis lizards. Our results showed no negative effects of four months of captivity on physiological and behavioral measurements in male A carolinensis lizards. Similar results for females were found for all measurements except body mass and tail width. Here our results indicated a potential negative effect of four months of captivity on body mass and tail width in females.
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Affiliation(s)
- Glenn Borgmans
- Department of Biology, University of Antwerp Antwerp, Belgium.,Centre for Research and Conservation, Royal Zoological Society of Antwerp Antwerp Belgium
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Adina Sannen
- Ethology & Animal Welfare, Agro- & Biotechnology, HUB-ODISEE University College, Brussels, Belgium
| | - Hilde Vervaecke
- Ethology & Animal Welfare, Agro- & Biotechnology, HUB-ODISEE University College, Brussels, Belgium
| | - Raoul Van Damme
- Department of Biology, University of Antwerp Antwerp, Belgium
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14
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Lailvaux SP. It’s Not Easy Being Green: Behavior, Morphology, and Population Structure in Urban and Natural Populations of Green Anole (Anolis carolinensis) Lizards. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.570810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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15
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Campos SM, Rojas V, Wilczynski W. Arginine vasotocin impacts chemosensory behavior during social interactions of Anolis carolinensis lizards. Horm Behav 2020; 124:104772. [PMID: 32439348 DOI: 10.1016/j.yhbeh.2020.104772] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 01/10/2023]
Abstract
In reptiles, arginine vasotocin (AVT) impacts the performance of and response to visual social signals, but whether AVT also operates within the chemosensory system as arginine vasopressin (AVP) does in mammals is unknown, despite social odors being potent modifiers of competitive and appetitive behavior in reptiles. Here, we ask whether elevated levels of exogenous AVT impact rates of chemical display behavior (e.g. tongue flicks) in adult males, and whether conspecific males or females can chemically discriminate between competitor males based on differing levels of exogenous AVT in green anoles (Anolis carolinensis). We injected wild-caught green anole males with either AVT (AVT-Males) or a vehicle control (CON-Males) solution, then presented treated males with a conspecific stimulus (Intruder-Male or Intruder-Female) and filmed 30-minute interactions. We found that AVT-Males were faster than CON-Males to perform a tongue flick to conspecifics, and faster to chemically display toward Intruder-Females, suggesting AVT increased male interest in available chemical information during social encounters. Intruders performed more lip smack behavior when interacting with AVT-Males than with CON-Males, and Intruder-Males performed more tongue flick behavior when interacting with AVT-Males than with CON-Males, suggesting anoles can discriminate between conspecifics based on exogenous AVT levels. We also found a reduction in Intruder movement behavior when Intruders were paired with AVT-Males. This study provides empirical support for AVT-mediated chemosensory behavior in reptilian social interactions, in a microsmatic lizard species, suggesting the mechanism by which mammalian AVP and non-mammalian AVT mediate chemosensory behavior during social interactions may be evolutionarily conserved.
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Affiliation(s)
- Stephanie M Campos
- Georgia State University, Neuroscience Institute and Center for Behavioral Neuroscience, Atlanta, GA, USA.
| | - Valentina Rojas
- Universidad del Bío-Bío, Concepción, Chile; Universidad Catolica del Maule, Talca, Chile
| | - Walter Wilczynski
- Georgia State University, Neuroscience Institute and Center for Behavioral Neuroscience, Atlanta, GA, USA
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Taylor EN, Diele‐Viegas LM, Gangloff EJ, Hall JM, Halpern B, Massey MD, Rödder D, Rollinson N, Spears S, Sun B, Telemeco RS. The thermal ecology and physiology of reptiles and amphibians: A user's guide. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 335:13-44. [DOI: 10.1002/jez.2396] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/12/2020] [Accepted: 06/13/2020] [Indexed: 02/05/2023]
Affiliation(s)
- Emily N. Taylor
- Biological Sciences Department California Polytechnic State University San Luis Obispo California
| | | | | | - Joshua M. Hall
- Department of Biological Sciences Auburn University Auburn Alabama
| | | | - Melanie D. Massey
- Department of Biology Dalhousie University Halifax Nova Scotia Canada
| | - Dennis Rödder
- Zoologisches Forschungsmuseum Alexander Koenig Bonn Germany
| | - Njal Rollinson
- Department of Ecology and Evolutionary Biology University of Toronto St. Toronto Ontario Canada
- School of the Environment University of Toronto Toronto Ontario Canada
| | - Sierra Spears
- Department of Zoology Ohio Wesleyan University Delaware Ohio
| | - Bao‐jun Sun
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology Chinese Academy of Sciences Beijing China
| | - Rory S. Telemeco
- Department of Biology California State University Fresno California
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17
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Transcriptional analysis of scar-free wound healing during early stages of tail regeneration in the green anole lizard, Anolis carolinensis. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.regen.2019.100025] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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18
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Borgmans G, Van den Panhuyzen S, Van Damme R. The (dis)advantages of dominance in a multiple male group of Anolis carolinensis lizards. ZOOLOGY 2020; 139:125747. [PMID: 32062300 DOI: 10.1016/j.zool.2020.125747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 01/04/2020] [Accepted: 01/16/2020] [Indexed: 10/25/2022]
Abstract
Male Anolis carolinensis lizards will fight and form social dominance hierarchies when placed in habitats with limited resources. Dominance may procure benefits such as priority access to food, shelter or partners, but may also come with costs, such as a higher risk of injuries due to aggressive interaction, a higher risk of predation or a higher energetic cost, all of which may lead to an increase in stress. While most research looks at dominance by using dyadic interactions, in our study we investigated the effect of dominance in a multiple male group of A. carolinensis lizards. Our results showed that dominant males in a multiple male group had priority access to prey and potential sexual partners but may run a higher risk of predation. We could not confirm that dominant males in a multiple male group had a higher risk of injuries from aggressive interactions or a higher energetic cost by being dominant. Overall our results seem to indicate that dominant male A. carolinensis lizards in a multiple male group obtain clear benefits and that they outweigh the disadvantages.
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Affiliation(s)
- Glenn Borgmans
- Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium; Centre for Research and Conservation, Royal Zoological Society of Antwerp, Antwerp, Belgium.
| | | | - Raoul Van Damme
- Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
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Van Dyke JU, Thompson MB, Burridge CP, Castelli MA, Clulow S, Dissanayake DSB, Dong CM, Doody JS, Edwards DL, Ezaz T, Friesen CR, Gardner MG, Georges A, Higgie M, Hill PL, Holleley CE, Hoops D, Hoskin CJ, Merry DL, Riley JL, Wapstra E, While GM, Whiteley SL, Whiting MJ, Zozaya SM, Whittington CM. Australian lizards are outstanding models for reproductive biology research. AUST J ZOOL 2020. [DOI: 10.1071/zo21017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Australian lizards are a diverse group distributed across the continent and inhabiting a wide range of environments. Together, they exhibit a remarkable diversity of reproductive morphologies, physiologies, and behaviours that is broadly representative of vertebrates in general. Many reproductive traits exhibited by Australian lizards have evolved independently in multiple lizard lineages, including sociality, complex signalling and mating systems, viviparity, and temperature-dependent sex determination. Australian lizards are thus outstanding model organisms for testing hypotheses about how reproductive traits function and evolve, and they provide an important basis of comparison with other animals that exhibit similar traits. We review how research on Australian lizard reproduction has contributed to answering broader evolutionary and ecological questions that apply to animals in general. We focus on reproductive traits, processes, and strategies that are important areas of current research, including behaviours and signalling involved in courtship; mechanisms involved in mating, egg production, and sperm competition; nesting and gestation; sex determination; and finally, birth in viviparous species. We use our review to identify important questions that emerge from an understanding of this body of research when considered holistically. Finally, we identify additional research questions within each topic that Australian lizards are well suited for reproductive biologists to address.
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Bourgeois Y, Boissinot S. Selection at behavioural, developmental and metabolic genes is associated with the northward expansion of a successful tropical colonizer. Mol Ecol 2019; 28:3523-3543. [PMID: 31233650 DOI: 10.1111/mec.15162] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 05/28/2019] [Indexed: 02/06/2023]
Abstract
What makes a species able to colonize novel environments? This question is key to understand the dynamics of adaptive radiations and ecological niche shifts, but the mechanisms that underlie expansion into novel habitats remain poorly understood at a genomic scale. Lizards from the genus Anolis are typically tropical, and the green anole (Anolis carolinensis) constitutes an exception since it expanded into temperate North America from subtropical Florida. Thus, we used the green anole as a model to investigate signatures of selection associated with colonization of a new environment, namely temperate North America. To this end, we analysed 29 whole-genome sequences, covering the entire native range of the species. We used a combination of recent methods to quantify both positive and balancing selection in northern populations, including FST outlier methods, machine learning and ancestral recombination graphs. We naively scanned for genes of interest and assessed the overlap between multiple tests. Strikingly, we identified many genes involved in behaviour, suggesting that the recent successful colonization of northern environments may have been linked to behavioural shifts as well as physiological adaptation. Using a candidate genes strategy, we determined that genes involved in response to cold or behaviour displayed more frequently signals of selection, while controlling for local recombination rate, gene clustering and gene length. In addition, we found signatures of balancing selection at immune genes in all investigated genetic groups, but also at genes involved in neuronal and anatomical development.
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Affiliation(s)
- Yann Bourgeois
- New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
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21
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Bodden V, Puschendorf R. Morphological divergence and reduced ectoparasite prevalence in an introduced population of a Caribbean anole. J Zool (1987) 2019. [DOI: 10.1111/jzo.12664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- V. Bodden
- School of Biological and Marine Sciences University of Plymouth Plymouth UK
| | - R. Puschendorf
- School of Biological and Marine Sciences University of Plymouth Plymouth UK
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22
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Moon RM, Kamath A. Re-examining escape behaviour and habitat use as correlates of dorsal pattern variation in female brown anole lizards,Anolis sagrei(Squamata: Dactyloidae). Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Rachel M Moon
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Ambika Kamath
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
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23
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Sannan NS, Shan X, Gregory-Evans K, Kusumi K, Gregory-Evans CY. Anolis carolinensis as a model to understand the molecular and cellular basis of foveal development. Exp Eye Res 2018; 173:138-147. [DOI: 10.1016/j.exer.2018.05.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/02/2018] [Accepted: 05/14/2018] [Indexed: 12/12/2022]
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24
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Pačuta A, Žagar A, Kočíková B, Majláthová V, Mihalca AD, Majláth I. Time matters. Locomotor behavior of Lacerta viridis and Lacerta agilis in an open field maze. Acta Ethol 2018. [DOI: 10.1007/s10211-018-0287-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Rupp SM, Webster TH, Olney KC, Hutchins ED, Kusumi K, Wilson Sayres MA. Evolution of Dosage Compensation in Anolis carolinensis, a Reptile with XX/XY Chromosomal Sex Determination. Genome Biol Evol 2018; 9:231-240. [PMID: 28206607 PMCID: PMC5381669 DOI: 10.1093/gbe/evw263] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2016] [Indexed: 12/11/2022] Open
Abstract
In species with highly heteromorphic sex chromosomes, the degradation of one of the sex chromosomes will result in unequal gene expression between the sexes (e.g. between XX females and XY males) and between the sex chromosomes and the autosomes. Dosage compensation is a process whereby genes on the sex chromosomes achieve equal gene expression. We compared genome-wide levels of transcription between males and females, and between the X chromosome and the autosomes in the green anole, Anolis carolinensis. We present evidence for dosage compensation between the sexes, and between the sex chromosomes and the autosomes. When dividing the X chromosome into regions based on linkage groups, we discovered that genes in the first reported X-linked region, anole linkage group b (LGb), exhibit complete dosage compensation, although the rest of the X-linked genes exhibit incomplete dosage compensation. Our data further suggest that the mechanism of this dosage compensation is upregulation of the X chromosome in males. We report that approximately 10% of coding genes, most of which are on the autosomes, are differentially expressed between males and females. In addition, genes on the X chromosome exhibited higher ratios of nonsynonymous to synonymous substitution than autosomal genes, consistent with the fast-X effect. Our results from the green anole add an additional observation of dosage compensation in a species with XX/XY sex determination.
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Affiliation(s)
- Shawn M Rupp
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | | | - Kimberly C Olney
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | | | - Kenro Kusumi
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Melissa A Wilson Sayres
- School of Life Sciences, Arizona State University, Tempe, AZ, USA.,Center for Evolution and Medicine, The Biodesign Institute at Arizona State University, Tempe, AZ, USA
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Prey availability affects territory size, but not territorial display behavior, in green anole lizards. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2017. [DOI: 10.1016/j.actao.2017.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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27
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Wild JM. The ventromedial hypothalamic nucleus in the zebra finch (Taeniopygia guttata): Afferent and efferent projections in relation to the control of reproductive behavior. J Comp Neurol 2017; 525:2657-2676. [PMID: 28420031 DOI: 10.1002/cne.24225] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 01/11/2023]
Abstract
Sex-specific mating behaviors occur in a variety of mammals, with the medial preoptic nucleus (POM) and the ventromedial hypothalamic nucleus (VMH) mediating control of male and female sexual behavior, respectively. In birds, likewise, POM is predominantly involved in the control of male reproductive behavior, but the degree to which VMH is involved in female reproductive behavior is unclear. Here, in male and female zebra finches, a combination of aromatase immunohistochemistry and conventional tract tracing facilitated the definition of two separate but adjacent nuclei in the basal hypothalamus: an oblique band of aromatase-positive (AR+) neurons, and ventromedial to this, an ovoid, aromatase-negative (AR-) nucleus. The AR- nucleus, but not the AR+ nucleus, was here shown to receive a projection from rostral parts of the thalamic auditory nucleus ovoidalis and from the nucleus of the tractus ovoidalis. The AR- nucleus also receives an overlapping, major projection from previously uncharted regions of the medial arcopallium and a minor projection from the caudomedial nidopallium. Both the AR- and the AR+ nuclei project to the intercollicular nucleus of the midbrain. No obvious sex differences in either the pattern of AR immunoreactivity or of the afferent projections to the AR- nucleus were observed. The significance of these results in terms of the acoustic control of avian reproductive behavior is discussed, and a comparison with the organization of VMH afferents in lizards suggests a homologous similarity of the caudal telencephalon in sauropsids.
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Affiliation(s)
- J Martin Wild
- Faculty of Medical and Health Sciences, Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
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28
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Neuman-Lee L, Greives T, Hopkins GR, French SS. The role of the kisspeptin system in regulation of the reproductive endocrine axis and territorial behavior in male side-blotched lizards (Uta stansburiana). Horm Behav 2017; 89:48-54. [PMID: 28017596 DOI: 10.1016/j.yhbeh.2016.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/23/2016] [Accepted: 12/12/2016] [Indexed: 11/18/2022]
Abstract
The neuropeptide kisspeptin and its receptor are essential for activation of the hypothalamic-pituitary-gonadal (HPG) axis and regulating reproduction. While the role of kisspeptin in regulating the HPG axis in mammals has been well established, little is known about the functional ability of kisspeptins to activate the HPG axis and associated behavior in non-mammalian species. Here we experimentally examined the effects of kisspeptin on downstream release of testosterone and associated aggression and display behaviors in the side-blotched lizard (Uta stansburiana). We found that exogenous treatment with kisspeptin resulted in an increase in circulating testosterone levels, castration blocked the kisspeptin-induced increase in testosterone, and testosterone levels in kisspeptin-treated animals were positively related to frequency of aggressive behaviors. This evidence provides a clear link between kisspeptin, testosterone, and aggressive behavior in lizards. Thus, it is likely that kisspeptin plays an important role more broadly in non-mammalian systems in the regulation of reproductive physiology and related behaviors.
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Affiliation(s)
- Lorin Neuman-Lee
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, USA
| | - Timothy Greives
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58106, USA
| | - Gareth R Hopkins
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, USA
| | - Susannah S French
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, USA; The Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5205, USA.
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Abstract
This chapter provides an introduction to animals that are commonly used for research. It presents information on basic care topics such as biology, behavior, housing, feeding, sexing, and breeding of these animals. The chapter provides some insight into the reasons why these animals are used in research. It also gives an overview of techniques that can be utilized to collect blood or to administer drugs or medicine. Each section concludes with a brief description of how to recognize abnormal signs, in addition to lists of various diseases.
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Manthey JD, Tollis M, Lemmon AR, Moriarty Lemmon E, Boissinot S. Diversification in wild populations of the model organism Anolis carolinensis: A genome-wide phylogeographic investigation. Ecol Evol 2016; 6:8115-8125. [PMID: 27891220 PMCID: PMC5108263 DOI: 10.1002/ece3.2547] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/14/2016] [Accepted: 09/19/2016] [Indexed: 01/14/2023] Open
Abstract
The green anole (Anolis carolinensis) is a lizard widespread throughout the southeastern United States and is a model organism for the study of reproductive behavior, physiology, neural biology, and genomics. Previous phylogeographic studies of A. carolinensis using mitochondrial DNA and small numbers of nuclear loci identified conflicting and poorly supported relationships among geographically structured clades; these inconsistencies preclude confident use of A. carolinensis evolutionary history in association with morphological, physiological, or reproductive biology studies among sampling localities and necessitate increased effort to resolve evolutionary relationships among natural populations. Here, we used anchored hybrid enrichment of hundreds of genetic markers across the genome of A. carolinensis and identified five strongly supported phylogeographic groups. Using multiple analyses, we produced a fully resolved species tree, investigated relative support for each lineage across all gene trees, and identified mito‐nuclear discordance when comparing our results to previous studies. We found fixed differences in only one clade—southern Florida restricted to the Everglades region—while most polymorphisms were shared between lineages. The southern Florida group likely diverged from other populations during the Pliocene, with all other diversification during the Pleistocene. Multiple lines of support, including phylogenetic relationships, a latitudinal gradient in genetic diversity, and relatively more stable long‐term population sizes in southern phylogeographic groups, indicate that diversification in A. carolinensis occurred northward from southern Florida.
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Affiliation(s)
| | - Marc Tollis
- Biodesign Institute Arizona State University Tempe AZ USA
| | - Alan R Lemmon
- Department of Scientific Computing Florida State University Tallahassee FL USA
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31
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Bush JM, Quinn MM, Balreira EC, Johnson MA. How do lizards determine dominance? Applying ranking algorithms to animal social behaviour. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.04.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jaffe AL, Campbell-Staton SC, Losos JB. Geographical variation in morphology and its environmental correlates in a widespread North American lizard,Anolis carolinensis(Squamata: Dactyloidae). Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12711] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alexander L. Jaffe
- Department of Organismic and Evolutionary Biology; Harvard University; Cambridge MA 02138 USA
| | | | - Jonathan B. Losos
- Department of Organismic and Evolutionary Biology; Harvard University; Cambridge MA 02138 USA
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Maximino C, Silva RXDC, da Silva SDNS, Rodrigues LDSDS, Barbosa H, de Carvalho TS, Leão LKDR, Lima MG, Oliveira KRM, Herculano AM. Non-mammalian models in behavioral neuroscience: consequences for biological psychiatry. Front Behav Neurosci 2015; 9:233. [PMID: 26441567 PMCID: PMC4561806 DOI: 10.3389/fnbeh.2015.00233] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 08/18/2015] [Indexed: 01/04/2023] Open
Abstract
Current models in biological psychiatry focus on a handful of model species, and the majority of work relies on data generated in rodents. However, in the same sense that a comparative approach to neuroanatomy allows for the identification of patterns of brain organization, the inclusion of other species and an adoption of comparative viewpoints in behavioral neuroscience could also lead to increases in knowledge relevant to biological psychiatry. Specifically, this approach could help to identify conserved features of brain structure and behavior, as well as to understand how variation in gene expression or developmental trajectories relates to variation in brain and behavior pertinent to psychiatric disorders. To achieve this goal, the current focus on mammalian species must be expanded to include other species, including non-mammalian taxa. In this article, we review behavioral neuroscientific experiments in non-mammalian species, including traditional "model organisms" (zebrafish and Drosophila) as well as in other species which can be used as "reference." The application of these domains in biological psychiatry and their translational relevance is considered.
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Affiliation(s)
- Caio Maximino
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Rhayra Xavier do Carmo Silva
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Suéllen de Nazaré Santos da Silva
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Laís do Socorro dos Santos Rodrigues
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Hellen Barbosa
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Tayana Silva de Carvalho
- Universität Duisburg-EssenEssen, Germany
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
| | - Luana Ketlen dos Reis Leão
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
| | - Monica Gomes Lima
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
| | - Karen Renata Matos Oliveira
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
| | - Anderson Manoel Herculano
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
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Byers JA. Earwigs (Labidura riparia) mimic rotting-flesh odor to deceive vertebrate predators. THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 2015; 102:38. [PMID: 26071006 DOI: 10.1007/s00114-015-1288-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 05/28/2015] [Accepted: 06/01/2015] [Indexed: 11/25/2022]
Abstract
Many insects repel predators with caustic chemicals, while insects mimicking odors of wastes/dead insects to fool predators have not been documented. We found that the shore earwig, Labidura riparia (Dermaptera: Labiduridae) when bitten by anole lizards, Anolis carolinenesus, spits a rotting-flesh odor that deceives these insectivores into rejecting prey. Once a lizard attacked and rejected an earwig, the lizard did not attack another earwig during several weeks despite consuming other prey, indicating associative learning after one trial. The fetid odor was found in the head-prothorax containing salivary glands of both male and female earwigs and was comprised of ∼ 100 ng dimethyl disulfide and ∼ 600 ng dimethyl trisulfide. Nymphs had <5 ng of either compound. Adults also spit odorous sulfides after prolonged attacks by harvester ants, Pogonomyrmex rugosus, who were only deterred by the earwig's forceps. Sulfides released by the earwig are similar to odors of carrion/feces, which may be innately repulsive to some vertebrate predators. The mean initial discharge percentage (IDP) of sulfides from a cohort of earwigs was 62 %; however, IDPs of individuals were highly variable (3-99 %; mean 57 %). The discharge refill time (DRT) to refill 50 % of the earwig's allomone reservoir was estimated at 13 h. A positive relationship in sulfide amounts with body weight was found only in females in 2009, suggesting metabolic cost tradeoffs were revealed when sulfide content was half that in 2010. This is the first report of insects releasing sulfur-containing compounds that may mimic carrion-fecal odors as a deceptive defense against vertebrate predators.
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Affiliation(s)
- John A Byers
- USDA-ARS, US Arid-Land Agricultural Research Center, 21881 North Cardon Lane, Maricopa, AZ, 85138, USA,
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Macedonia JM, Clark DL, Cherry LE, Mohamed NE, Bartel BW. Comparison of Headbob Displays in Gray-Dewlapped and Red-Dewlapped Populations of Green Anoles (Anolis carolinensis). HERPETOLOGICA 2015. [DOI: 10.1655/herpetologica-d-14-00045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kerver HN, Wade J. Relationships among sex, season and testosterone in the expression of androgen receptor mRNA and protein in the green anole forebrain. BRAIN, BEHAVIOR AND EVOLUTION 2014; 84:303-14. [PMID: 25471151 DOI: 10.1159/000368388] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 09/12/2014] [Indexed: 11/19/2022]
Abstract
Sexual behavior in male green anole lizards is regulated by a seasonal increase in testosterone (T). However, T is much more effective at activating behavioral, morphological and biochemical changes related to reproduction in the breeding season (BS; spring) compared to nonbreeding season (NBS; fall). An increase in androgen receptor (AR) during the BS is one potential mechanism for this differential responsiveness. AR expression has not been investigated in specific brain regions across seasons in anoles. The present studies were designed to determine relative AR expression in areas important for male (preoptic area, ventromedial amygdala) and female (ventromedial hypothalamus) sexual behavior, as well as whether T upregulates AR in the anole brain. In situ hybridization and Western blot analyses were performed in unmanipulated animals across sex and season, as well as in gonadectomized animals with and without T treatment. Among hormone-manipulated animals, more cells expressing AR mRNA were detected in females than males in the amygdala. T treatment increased the volume of the ventromedial hypothalamus of gonadectomized animals in the BS, but not the NBS. AR protein in dissections of the hypothalamus and preoptic area was increased in males compared to females specifically in the BS. Additionally, among females, it was increased in the NBS compared to the BS. Collectively, these results indicate that differences in central AR expression probably do not facilitate a seasonal responsiveness to T. However, they are consistent with a role for AR in regulating some differences between sexes in the display of reproductive behaviors.
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Affiliation(s)
- Halie N Kerver
- Neuroscience Program, Michigan State University, East Lansing, Mich., USA
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Tollis M, Boissinot S. Lizards and LINEs: selection and demography affect the fate of L1 retrotransposons in the genome of the green anole (Anolis carolinensis). Genome Biol Evol 2014; 5:1754-68. [PMID: 24013105 PMCID: PMC3787681 DOI: 10.1093/gbe/evt133] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Autonomous retrotransposons lacking long terminal repeats (LTR) account for much of the variation in genome size and structure among vertebrates. Mammalian genomes contain hundreds of thousands of non-LTR retrotransposon copies, mostly resulting from the amplification of a single clade known as L1. The genomes of teleost fish and squamate reptiles contain a much more diverse array of non-LTR retrotransposon families, whereas copy number is relatively low. The majority of non-LTR retrotransposon insertions in nonmammalian vertebrates also appear to be very recent, suggesting strong purifying selection limits the accumulation of non-LTR retrotransposon copies. It is however unclear whether this turnover model, originally proposed in Drosophila, applies to nonmammalian vertebrates. Here, we studied the population dynamics of L1 in the green anole lizard (Anolis carolinensis). We found that although most L1 elements are recent in this genome, truncated insertions accumulate readily, and many are fixed at both the population and species level. In contrast, full-length L1 insertions are found at lower population frequencies, suggesting that the turnover model only applies to longer L1 elements in Anolis. We also found that full-length L1 inserts are more likely to be fixed in populations of small effective size, suggesting that the strength of purifying selection against deleterious alleles is highly dependent on host demographic history. Similar mechanisms seem to be controlling the fate of non-LTR retrotransposons in both Anolis and teleostean fish, which suggests that mammals have considerably diverged from the ancestral vertebrate in terms of how they interact with their intragenomic parasites.
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Affiliation(s)
- Marc Tollis
- Biology Department, Queens College, City University of New York, Flushing
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Tollis M, Boissinot S. Genetic variation in the green anole lizard (Anolis carolinensis) reveals island refugia and a fragmented Florida during the quaternary. Genetica 2013; 142:59-72. [PMID: 24379168 DOI: 10.1007/s10709-013-9754-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 12/23/2013] [Indexed: 11/27/2022]
Abstract
The green anole lizard (Anolis carolinensis) is a model organism for behavior and genomics that is native to the southeastern United States. It is currently thought that the ancestors of modern green anoles dispersed to peninsular Florida from Cuba. However, the climatic changes and geological features responsible for the early diversification of A. carolinensis in North America have remained largely unexplored. This is because previous studies (1) differ in their estimates of the divergence times of populations, (2) are based on a single genetic locus or (3) did not test specific hypotheses regarding the geologic and topographic history of Florida. Here we provide a multi-locus study of green anole genetic diversity and find that the Florida peninsula contains a larger number of genetically distinct populations that are more diverse than those on the continental mainland. As a test of the island refugia hypothesis in Pleistocene Florida, we use a coalescent approach to estimate the divergence times of modern green anole lineages. We find that all demographic events occurred during or after the Upper Pliocene and suggest that green anole diversification was driven by population divergence on interglacial island refugia in Florida during the Lower Pleistocene, while the region was often separated from continental North America. When Florida reconnected to the mainland, two separate dispersal events led to the expansion of green anole populations across the Atlantic Seaboard and Gulf Coastal Plain.
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Affiliation(s)
- Marc Tollis
- Biology Department, Queens College, City University of New York (CUNY), 65-30 Kissena Boulevard, Flushing, New York, NY, USA,
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Kerver HN, Wade J. Seasonal and sexual dimorphisms in expression of androgen receptor and its coactivators in brain and peripheral copulatory tissues of the green anole. Gen Comp Endocrinol 2013; 193:56-67. [PMID: 23892016 DOI: 10.1016/j.ygcen.2013.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 06/14/2013] [Accepted: 07/08/2013] [Indexed: 12/22/2022]
Abstract
Green anoles are seasonally breeding lizards, with an annual rise in testosterone (T) being the primary activator of male sexual behaviors. Responsiveness to T is decreased in the non-breeding season (NBS) compared to breeding season (BS) on a variety of levels, including displays of reproductive behavior and the morphology and biochemistry of associated tissues. To evaluate the possibility that seasonal changes in responsiveness to T are regulated by androgen receptors (AR) and/or two of its coactivators, CREB binding protein (CBP) and steroid receptor coactivator-1 (SRC-1), we tested whether they differ in expression across season in brains of both sexes and in peripheral copulatory tissues of males (hemipenis and retractor penis magnus muscle). AR mRNA was increased in the brains of males compared to females and in copulatory muscle in the BS compared to NBS. In the hemipenis, transcriptional activity appeared generally diminished in the NBS. T-treatment increased AR mRNA in the copulatory muscle and AR protein in the hemipenis, the latter to a greater extent in the BS than the NBS. T also decreased SRC-1 protein in hemipenis. Interpretations are complicated, in part because levels of mRNA and protein expression were not correlated and multiple sizes of the AR and CBP proteins were detected, with some tissue specificity. However, the results are consistent with the idea that differences in receptor and coactivator expression at central and peripheral levels may play roles in regulating sex and seasonal differences in the motivation or physical ability to engage in sexual behavior.
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Affiliation(s)
- Halie N Kerver
- Neuroscience Program, Michigan State University, East Lansing, MI 48824-1101, United States.
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Toda M, Komatsu N, Takahashi H, Nakagawa N, Sukigara N. Fecundity in Captivity of the Green Anoles,Anolis carolinensis, Established on the Ogasawara Islands. CURRENT HERPETOLOGY 2013. [DOI: 10.5358/hsj.32.82] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Dill AK, Sanger TJ, Battles AC, Johnson MA. Sexual dimorphisms in habitat‐specific morphology and behavior in the green anole lizard. J Zool (1987) 2013. [DOI: 10.1111/jzo.12020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A. K. Dill
- Department of Biology Trinity University San Antonio TX USA
| | - T. J. Sanger
- Museum of Comparative Zoology Harvard University Cambridge MA USA
- Department of Organismic and Evolutionary Biology Harvard University Cambridge MA USA
| | - A. C. Battles
- Department of Biology Trinity University San Antonio TX USA
| | - M. A. Johnson
- Department of Biology Trinity University San Antonio TX USA
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Campbell-Staton SC, Goodman RM, Backström N, Edwards SV, Losos JB, Kolbe JJ. Out of Florida: mtDNA reveals patterns of migration and Pleistocene range expansion of the Green Anole lizard (Anolis carolinensis). Ecol Evol 2012; 2:2274-84. [PMID: 23139885 PMCID: PMC3488677 DOI: 10.1002/ece3.324] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 06/09/2012] [Accepted: 06/18/2012] [Indexed: 11/09/2022] Open
Abstract
Anolis carolinensis is an emerging model species and the sole member of its genus native to the United States. Considerable morphological and physiological variation has been described in the species, and the recent sequencing of its genome makes it an attractive system for studies of genome variation. To inform future studies of molecular and phenotypic variation within A. carolinensis, a rigorous account of intraspecific population structure and relatedness is needed. Here, we present the most extensive phylogeographic study of this species to date. Phylogenetic analyses of mitochondrial DNA sequence data support the previous hypothesis of a western Cuban origin of the species. We found five well-supported, geographically distinct mitochondrial haplotype clades throughout the southeastern United States. Most Florida populations fall into one of three divergent clades, whereas the vast majority of populations outside Florida belong to a single, shallowly diverged clade. Genetic boundaries do not correspond to major rivers, but may reflect effects of Pleistocene glaciation events and the Appalachian Mountains on migration and expansion of the species. Phylogeographic signal should be examined using nuclear loci to complement these findings.
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Affiliation(s)
- Shane C Campbell-Staton
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University Cambridge, MA, 02138
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Ritzman TB, Stroik LK, Julik E, Hutchins ED, Lasku E, Denardo DF, Wilson-Rawls J, Rawls JA, Kusumi K, Fisher RE. The Gross Anatomy of the Original and Regenerated Tail in the Green Anole (Anolis carolinensis). Anat Rec (Hoboken) 2012; 295:1596-608. [DOI: 10.1002/ar.22524] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 05/25/2012] [Accepted: 06/04/2012] [Indexed: 11/11/2022]
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Tollis M, Ausubel G, Ghimire D, Boissinot S. Multi-locus phylogeographic and population genetic analysis of Anolis carolinensis: historical demography of a genomic model species. PLoS One 2012; 7:e38474. [PMID: 22685573 PMCID: PMC3369884 DOI: 10.1371/journal.pone.0038474] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 05/07/2012] [Indexed: 11/19/2022] Open
Abstract
The green anole (Anolis carolinensis) has been widely used as an animal model in physiology and neurobiology but has recently emerged as an important genomic model. The recent sequencing of its genome has shed new light on the evolution of vertebrate genomes and on the process that govern species diversification. Surprisingly, the patterns of genetic diversity within natural populations of this widespread and abundant North American lizard remain relatively unknown. In the present study, we use 10 novel nuclear DNA sequence loci (N = 62 to 152) and one mitochondrial locus (N = 226) to delimit green anole populations and infer their historical demography. We uncovered four evolutionarily distinct and geographically restricted lineages of green anoles using phylogenetics, bayesian clustering, and genetic distance methods. Molecular dating indicates that these lineages last shared a common ancestor ∼2 million years ago. Summary statistics and analysis of the frequency distributions of DNA polymorphisms strongly suggest range-wide expansions in population size. Using Bayesian Skyline Plots, we inferred the timing of population size expansions, which differ across lineages, and found evidence for a relatively recent and rapid westward expansion of green anoles across the Gulf Coastal Plain during the mid-Pleistocene. One surprising result is that the distribution of genetic diversity is not consistent with a latitudinal shift caused by climatic oscillations as is observed for many co-distributed taxa. This suggests that the most recent Pleistocene glacial cycles had a limited impact on the geographic distribution of the green anole at the northern limits of its range.
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Affiliation(s)
- Marc Tollis
- Biology Department, Queens College, City University of New York, Flushing, New York, United States of America
- Biology Program: Ecology, Evolutionary Biology and Behavior, Graduate Center, City University of New York, New York, New York, United States of America
| | - Gavriel Ausubel
- Biology Department, Queens College, City University of New York, Flushing, New York, United States of America
| | - Dhruba Ghimire
- Biology Department, Queens College, City University of New York, Flushing, New York, United States of America
| | - Stéphane Boissinot
- Biology Department, Queens College, City University of New York, Flushing, New York, United States of America
- Biology Program: Ecology, Evolutionary Biology and Behavior, Graduate Center, City University of New York, New York, New York, United States of America
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McMurry ST, Jones LE, Smith PN, Cobb GP, Anderson TA, Lovern MB, Cox S, Pan X. Accumulation and effects of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) exposure in the green anole (Anolis carolinensis). ECOTOXICOLOGY (LONDON, ENGLAND) 2012; 21:304-314. [PMID: 21947615 DOI: 10.1007/s10646-011-0791-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/12/2011] [Indexed: 05/31/2023]
Abstract
Environmental contamination by energetic compounds is an increasing international concern, although little is known of their accumulation in and affect on wildlife. Reptiles are often good models for contaminants studies due to natural history traits that increase their potential for exposure. We report a study to assess accumulation and effects of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX, High Melting Explosive) in green anoles (Anolis carolinensis). Acute oral toxicity (LD(50)) was estimated to exceed 2000 mg/kg body weight in adult male and female anoles using a standard up-and-down method. Accumulation of HMX was assessed in adult females via dietary exposure and into eggs by two routes (directly from the soil and via maternal transfer). HMX readily accumulated into adult females in a dose-dependent manner and into eggs following both exposure pathways. However, total HMX in soil-exposed eggs was up to 40-times greater than those exposed via maternal transfer. Although there was a suggestion of an HMX-induced reduction in body weight in adult females, overall there were no effects observed over the 12 week exposure period. The only significant effect on eggs was a 50% reduction in hatching success for eggs exposed to 2000 mg/kg HMX in the soil during incubation. Growth and survival of hatchlings was not affected by HMX exposure. Our results demonstrate that HMX accumulates through the food chain and into eggs from the soil, but likely poses minimal threat to lizards except to hatching success in eggs incubated in soils with HMX levels near maximum environmental concentrations.
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Affiliation(s)
- S T McMurry
- Department of Zoology, Oklahoma State University, Stillwater, OK 74078, USA.
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Wade J. Relationships among hormones, brain and motivated behaviors in lizards. Horm Behav 2011; 59:637-44. [PMID: 20816970 DOI: 10.1016/j.yhbeh.2010.08.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Accepted: 08/25/2010] [Indexed: 11/22/2022]
Abstract
Lizards provide a rich opportunity for investigating the mechanisms associated with arousal and the display of motivated behaviors. They exhibit diverse mating strategies and modes of conspecific communication. This review focuses on anole lizards, of which green anoles (Anolis carolinensis) have been most extensively studied. Research from other species is discussed in that context. By considering mechanisms collectively, we can begin to piece together neural and endocrine factors mediating the stimulation of sexual and aggressive behaviors in this group of vertebrates.
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Affiliation(s)
- Juli Wade
- Michigan State University, Department of Psychology, East Lansing, MI 48824, USA.
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Rhen T, Schroeder A. Molecular mechanisms of sex determination in reptiles. Sex Dev 2010; 4:16-28. [PMID: 20145384 PMCID: PMC2918650 DOI: 10.1159/000282495] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 08/15/2009] [Indexed: 01/17/2023] Open
Abstract
Charles Darwin first provided a lucid explanation of how gender differences evolve nearly 140 years ago. Yet, a disconnect remains between his theory of sexual selection and the mechanisms that underlie the development of males and females. In particular, comparisons between representatives of different phyla (i.e., flies and mice) reveal distinct genetic mechanisms for sexual differentiation. Such differences are hard to comprehend unless we study organisms that bridge the phylogenetic gap. Analysis of variation within monophyletic groups (i.e., amniotes) is just as important if we hope to elucidate the evolution of mechanisms underlying sexual differentiation. Here we review the molecular, cellular, morphological, and physiological changes associated with sex determination in reptiles. Most research on the molecular biology of sex determination in reptiles describes expression patterns for orthologs of mammalian sex-determining genes. Many of these genes have evolutionarily conserved expression profiles (i.e., DMRT1 and SOX9 are expressed at a higher level in developing testes vs. developing ovaries in all species), which suggests functional conservation. However, expression profiling alone does not test gene function and will not identify novel sex-determining genes or gene interactions. For that reason, we provide a prospectus on various techniques that promise to reveal new sex-determining genes and regulatory interactions among these genes. We offer specific examples of novel candidate genes and a new signaling pathway in support of these techniques.
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Affiliation(s)
- T. Rhen
- Department of Biology, University of North Dakota, Grand Forks, N. Dak., USA
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Latham S, Wade J. Estradiol facilitates mounting behavior in male green anole lizards. Physiol Behav 2010; 99:78-81. [DOI: 10.1016/j.physbeh.2009.10.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 10/13/2009] [Accepted: 10/22/2009] [Indexed: 10/20/2022]
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Beck LA, Wade J. Morphology and estrogen receptor alpha mRNA expression in the developing green anole forebrain. ACTA ACUST UNITED AC 2009; 311:162-71. [PMID: 19065643 DOI: 10.1002/jez.514] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sex differences in forebrain morphology arise during development and are often linked to hormonal changes. These dimorphisms frequently occur in regions related to reproductive behaviors. Little is known about the normal ontogeny of reproductive nuclei in the green anole lizard, including whether steroid hormones influence their development. To address this issue, brain region volume, cell density, soma size, and estrogen receptor alpha (ERalpha) mRNA expression were characterized in the preoptic area (POA), ventromedial amygdala (AMY), and ventromedial hypothalamus (VMH) of late embryonic and early post-hatchling anoles. In adulthood, the POA and AMY are associated with male-specific reproductive behaviors and the VMH is implicated in female receptivity. Although soma size decreased in all brain regions with age, brain region volume diminished only in the POA, with a transient sex difference appearing before hatching. Cell density increased with age only in the female AMY. ERalpha mRNA expression was up to four times greater in the developing VMH than POA and AMY, peaking in the VMH around the day of hatching. These results are consistent with the idea that estradiol may influence differentiation of the VMH in particular. However, other factors are likely important to the development of these three brain regions, some of which exert their effects at later developmental stages.
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Affiliation(s)
- Laurel Amanda Beck
- Neuroscience Program, Michigan State University, East Lansing, Michigan 48824, USA.
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