26
|
Demırtaş S, Silsüpür M, Searle JB, Bilton D, Gündüz İ. What should we call the Levant mole? Unravelling the systematics and demography of Talpa levantis Thomas, 1906 sensu lato (Mammalia: Talpidae). Mamm Biol 2020. [DOI: 10.1007/s42991-020-00010-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
27
|
Arslan Y, Demi̇rtaş S, Herman JS, Pustilnik JD, Searle JB, Gündüz İ. The Anatolian glacial refugium and human-mediated colonization: a phylogeographical study of the stone marten (Martes foina) in Turkey. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
AbstractThe Anatolian Peninsula, comprising most of modern Turkey, is situated at the junction of Europe, the Middle East and Asia. Together with its complex geomorphological and climatic history, this has given rise to a rich fauna and flora, which exhibits a wide range of historical biogeographical patterns. The stone marten (Martes foina) is a small carnivore that is found across the temperate Palaearctic region including Anatolia, where it is often associated with habitats modified by humans, but few genetic data exist for this species. We sequenced a 1840-bp region of the mitochondrial genome from 97 martens sampled across the peninsula and intron 7 of the nuclear β-fibrinogen gene from 53 of these. Two mitochondrial lineages were recovered, with overlapping eastern and western distributions, but there was no geographical structure for the autosomal marker. Coalescent analyses indicated that both of the lineages originated during the Last Glacial Maximum, one of them within an eastern Anatolian refugium and the other in a western Anatolian or Balkan refugium. The western lineage colonized most of Europe in the Holocene, while the eastern lineage may be endemic to Anatolia, from where it colonized the Iberian Peninsula via human translocation. The presence of at least one refugial stone marten population highlights the importance of Anatolia to the preservation of genetic variation and biodiversity.
Collapse
|
28
|
Fletcher NK, Acevedo P, Herman JS, Paupério J, Alves PC, Searle JB. Glacial cycles drive rapid divergence of cryptic field vole species. Ecol Evol 2019; 9:14101-14113. [PMID: 31938506 PMCID: PMC6953675 DOI: 10.1002/ece3.5846] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 10/24/2019] [Indexed: 11/07/2022] Open
Abstract
Understanding the factors that contribute to the generation of reproductively isolated forms is a fundamental goal of evolutionary biology. Cryptic species are an especially interesting challenge to study in this context since they lack obvious morphological differentiation that provides clues to adaptive divergence that may drive reproductive isolation. Geographical isolation in refugial areas during glacial cycling is known to be important for generating genetically divergent populations, but its role in the origination of new species is still not fully understood and likely to be situation dependent. We combine analysis of 35,434 single-nucleotide polymorphisms (SNPs) with environmental niche modeling (ENM) to investigate genomic and ecological divergence in three cryptic species formerly classified as the field vole (Microtus agrestis). The SNPs demonstrate high genomic divergence (pairwise F ST values of 0.45-0.72) and little evidence of gene flow among the three field vole cryptic species, and we argue that genetic drift may have been a particularly important mechanism for divergence in the group. The ENM reveals three areas as potential glacial refugia for the cryptic species and differing climatic niches, although with spatial overlap between species pairs. This evidence underscores the role that glacial cycling has in promoting genetic differentiation and reproductive isolation by subdivision into disjunct distributions at glacial maxima in areas relatively close to ice sheets. Future investigation of the intrinsic barriers to gene flow between the field vole cryptic species is required to fully assess the mechanisms that contribute to reproductive isolation. In addition, the Portuguese field vole (M. rozianus) shows a high inbreeding coefficient and a restricted climatic niche, and warrants investigation into its conservation status.
Collapse
|
29
|
Campbell P, Arévalo L, Martin H, Chen C, Sun S, Rowe AH, Webster MS, Searle JB, Pasch B. Vocal divergence is concordant with genomic evidence for strong reproductive isolation in grasshopper mice ( Onychomys). Ecol Evol 2019; 9:12886-12896. [PMID: 31788222 PMCID: PMC6875671 DOI: 10.1002/ece3.5770] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 12/13/2022] Open
Abstract
Behavioral barriers to gene flow often evolve faster than intrinsic incompatibilities and can eliminate the opportunity for hybridization between interfertile species. While acoustic signal divergence is a common driver of premating isolation in birds and insects, its contribution to speciation in mammals is less studied. Here we characterize the incidence of, and potential barriers to, hybridization among three closely related species of grasshopper mice (genus Onychomys). All three species use long-distance acoustic signals to attract and localize mates; Onychomys arenicola and Onychomys torridus are acoustically similar and morphologically cryptic whereas Onychomys leucogaster is larger and acoustically distinct. We used genotyping-by-sequencing (GBS) to test for evidence of introgression in 227 mice from allopatric and sympatric localities in the western United States and northern Mexico. We conducted laboratory mating trials for all species pairs to assess reproductive compatibility, and recorded vocalizations from O. arenicola and O. torridus in sympatry and allopatry to test for evidence of acoustic character displacement. Hybridization was rare in nature and, contrary to prior evidence for O. torridus/O. arenicola hybrids, only involved O. leucogaster and O. arenicola. In contrast, laboratory crosses between O. torridus and O. arenicola produced litters whereas O. leucogaster and O. arenicola crosses did not. Call fundamental frequency in O. torridus and O. arenicola was indistinguishable in allopatry but significantly differentiated in sympatry, a pattern consistent with reproductive character displacement. These results suggest that assortative mating based on a long-distance signal is an important isolating mechanism between O. torridus and O. arenicola and highlight the importance of behavioral barriers in determining the permeability of species boundaries.
Collapse
|
30
|
Crumsey JM, Searle JB, Sparks JP. Isotope values of California vole (Microtus californicus) hair relate to historical drought and land use patterns in California, USA. Oecologia 2019; 190:769-781. [PMID: 31273518 DOI: 10.1007/s00442-019-04457-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 06/28/2019] [Indexed: 11/28/2022]
Abstract
Increased drought frequency and intensity and agricultural intensification have been key stressors to ecological systems over the past century. Biological proxies (e.g., pollen, tree rings) have been used to track this environmental change; however, linking these changes to the ecology of organisms remains challenging. Here, we link historical drought records to conditions of high water-stress in grassland habitats through the stable isotope analysis of California vole museum specimens (Microtus californicus). Using museum collections spanning 118-years (1891-2009), isotope values of dated hair tissues were associated with statewide drought metrics on the Palmer Drought Severity Index. We observed a positive correlation between δ15N and δ18O values and drought severity. The range in δ15N values (~ 18‰) is greater than what would be expected as a result of dietary shifts across the landscape (~ 3‰), and is likely attributed to the combined effects of physiological responses of M. californicus and isotopic shifts in plant resources with increased water-stress. Geospatial patterns in δ34S values of hair tissues reflect higher baseline isotope values in coastal habitats. However, comparably high δ34S values in the southern-most inland localities suggest sulfur fertilization of croplands and subsequent transfer to surrounding grassland habitats in 34S enriched forms. A broad δ13C range (- 28.7 to - 14.3‰) further suggests the consumption of C3 and C4 plant-based dietary proteins. As shown here, stable isotope analysis of museum collections can provide a climate and land use record based on the physiological performance and ecology of a study species in a region affected intensely by anthropogenic activities.
Collapse
|
31
|
Herman JS, Stojak J, Paupério J, Jaarola M, Wójcik JM, Searle JB. Genetic variation in field voles ( Microtus agrestis) from the British Isles: selective sweeps or population bottlenecks? Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/bly213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
32
|
Grize SA, Wilwert E, Searle JB, Lindholm AK. Measurements of hybrid fertility and a test of mate preference for two house mouse races with massive chromosomal divergence. BMC Evol Biol 2019; 19:25. [PMID: 30651079 PMCID: PMC6335807 DOI: 10.1186/s12862-018-1322-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 12/10/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Western house mice Mus musculus domesticus are among the most important mammalian model species for chromosomal speciation. Hybrids between chromosomal races of M. m. domesticus suffer various degrees of fertility reduction between full fertility and complete sterility, depending on the complexity of the chromosomal differences between the races. This complexity presents itself in hybrids as meiotic configurations of chromosome chains and rings, with longer configurations having a stronger impact on fertility. While hybrids with short configurations have been intensively studied, less work has been done on hybrids with very long configurations. In this study, we investigated laboratory-reared wild mice from two chromosomally very different races in Switzerland found in close proximity. Hybrids between these races form a meiotic chain of fifteen chromosomes. We performed a detailed analysis of male and female hybrid fertility, including three generations of female backcrosses to one of the parental races. We also tested for possible divergence of mate preference in females. RESULTS While all male F1 hybrids were sterile with sperm counts of zero, 48% of female F1 hybrids produced offspring. Their litter sizes ranged from one to three which is significantly lower than the litter size of parental race females. When hybrid females were backcrossed to a parental race, half of the offspring resembled the parental race in karyotype and fertility, while the other half resembled the F1 hybrids. In the preference test, females of both races indicated a lack of a preference for males of their own karyotype. CONCLUSIONS Although the fertility of the F1 hybrids was extremely low because of the complexity of the chromosomal differences between the races, reproductive isolation was not complete. As we did not find assortative female preferences, we expect that contact between these races would lead to the production of hybrids and that gene flow would occur eventually, as fertility can be restored fully after one backcross generation.
Collapse
|
33
|
Queirós J, Acevedo P, Santos JPV, Barasona J, Beltran-Beck B, González-Barrio D, Armenteros JA, Diez-Delgado I, Boadella M, Fernandéz de Mera I, Ruiz-Fons JF, Vicente J, de la Fuente J, Gortázar C, Searle JB, Alves PC. Red deer in Iberia: Molecular ecological studies in a southern refugium and inferences on European postglacial colonization history. PLoS One 2019; 14:e0210282. [PMID: 30620758 PMCID: PMC6324796 DOI: 10.1371/journal.pone.0210282] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 12/19/2018] [Indexed: 01/31/2023] Open
Abstract
The red deer (Cervus elaphus) is a widespread wild ungulate in Europe that has suffered strong anthropogenic impacts over their distribution during the last centuries, but also at the present time, due its economic importance as a game species. Here we focus on the evolutionary history of the red deer in Iberia, one of the three main southern refugial areas for temperate species in Europe, and addressed the hypothesis of a cryptic refugia at higher latitudes during the Last Glacial Maximum (LGM). A total of 911 individuals were sampled, genotyped for 34 microsatellites specifically developed for red deer and sequenced for a fragment of 670 bp of the mitochondrial (mtDNA) D-loop. The results were combined with published mtDNA sequences, and integrated with species distribution models and historical European paleo-distribution data, in order to further examine the alternative glacial refugial models and the influence of cryptic refugia on European postglacial colonization history. Clear genetic differentiation between Iberian and European contemporary populations was observed at nuclear and mtDNA levels, despite the mtDNA haplotypes central to the phylogenetic network are present across western Europe (including Iberia) suggesting a panmictic population in the past. Species distribution models, fossil records and genetic data support a timing of divergence between Iberian and European populations that overlap with the LGM. A notable population structure was also found within the Iberian Peninsula, although several populations displayed high levels of admixture as a consequence of recent red deer translocations. Five D-loop sub-lineages were found in Iberia that belong to the Western European mtDNA lineage, while there were four main clusters based on analysis of nuclear markers. Regarding glacial refugial models, our findings provide detailed support for the hypothesis that red deer may have persisted in cryptic northern refugia in western Europe during the LGM, most likely in southern France, southern Ireland, or in a region between them (continental shelf), and these regions were the source of individuals during the European re-colonization. This evidence heightens the importance of conserving the high mitochondrial and nuclear diversity currently observed in Iberian populations.
Collapse
|
34
|
Kotlík P, Marková S, Konczal M, Babik W, Searle JB. Genomics of end-Pleistocene population replacement in a small mammal. Proc Biol Sci 2019; 285:rspb.2017.2624. [PMID: 29436497 DOI: 10.1098/rspb.2017.2624] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/17/2018] [Indexed: 12/17/2022] Open
Abstract
Current species distributions at high latitudes are the product of expansion from glacial refugia into previously uninhabitable areas at the end of the last glaciation. The traditional view of postglacial colonization is that southern populations expanded their ranges into unoccupied northern territories. Recent findings on mitochondrial DNA (mtDNA) of British small mammals have challenged this simple colonization scenario by demonstrating a more complex genetic turnover in Britain during the Pleistocene-Holocene transition where one mtDNA clade of each species was replaced by another mtDNA clade of the same species. Here, we provide evidence from one of those small mammals, the bank vole (Clethrionomys glareolus), that the replacement was genome-wide. Using more than 10 000 autosomal SNPs we found that similar to mtDNA, bank vole genomes in Britain form two (north and south) clusters which admix. Therefore, the genome of the original postglacial colonists (the northern cluster) was probably replaced by another wave of migration from a different continental European population (the southern cluster), and we gained support for this by modelling with approximate Bayesian computation. This finding emphasizes the importance of analysis of genome-wide diversity within species under changing climate in creating opportunities for sophisticated testing of population history scenarios.
Collapse
|
35
|
Strážnická M, Marková S, Searle JB, Kotlík P. Playing Hide-and-Seek in Beta-Globin Genes: Gene Conversion Transferring a Beneficial Mutation between Differentially Expressed Gene Duplicates. Genes (Basel) 2018; 9:genes9100492. [PMID: 30321987 PMCID: PMC6209878 DOI: 10.3390/genes9100492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/07/2018] [Accepted: 10/10/2018] [Indexed: 12/17/2022] Open
Abstract
Increasing evidence suggests that adaptation to diverse environments often involves selection on existing variation rather than new mutations. A previous study identified a nonsynonymous single nucleotide polymorphism (SNP) in exon 2 of two paralogous β-globin genes of the bank vole (Clethrionomys glareolus) in Britain in which the ancestral serine (Ser) and the derived cysteine (Cys) allele represent geographically partitioned functional variation affecting the erythrocyte antioxidative capacity. Here we studied the geographical pattern of the two-locus Ser/Cys polymorphism throughout Europe and tested for the geographic correlation between environmental variables and allele frequency, expected if the polymorphism was under spatially heterogeneous environment-related selection. Although bank vole population history clearly is important in shaping the dispersal of the oxidative stress protective Cys allele, analyses correcting for population structure suggest the Europe-wide pattern is affected by geographical variation in environmental conditions. The β-globin phenotype is encoded by the major paralog HBB-T1 but we found evidence of bidirectional gene conversion of exon 2 with the low-expression paralog HBB-T2. Our data support the model where gene conversion reshuffling genotypes between high- and low- expressed paralogs enables tuning of erythrocyte thiol levels, which may help maintain intracellular redox balance under fluctuating environmental conditions. Therefore, our study suggests a possible role for gene conversion between differentially expressed gene duplicates as a mechanism of physiological adaptation of populations to new or changing environments.
Collapse
|
36
|
Hulme-Beaman A, Cucchi T, Evin A, Searle JB, Dobney K. Exploring Rattus praetor (Rodentia, Muridae) as a possible species complex using geometric morphometrics on dental morphology. Mamm Biol 2018; 92:62-67. [PMID: 30177868 PMCID: PMC6067089 DOI: 10.1016/j.mambio.2018.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Taxonomic uncertainties in the Rattus genus persist due to among-species morphological conservatism coupled with within-species environmental variation in morphology. As a result, this genus contains a number of possible cryptic species. One important example can be found in R. praetor, where morphological studies indicate it is a possible species complex. Genetic studies of R. praetor (limited to analysis of mitochondrial DNA) have been inconclusive, but do indicate such subdivision. Here we use geometric morphometrics to explore this possible species complex by analysing the dental traits of 48 specimens from New Guinea and neighbouring regions. We find separate molar morphologies for Bougainsville Island, central New Guinea and west New Guinea which cannot be easily explained by different environmental factors (climate, precipitation and altitude), strongly suggesting the existence of a number of evolutionarily distinct taxa within what is currently called R. praetor thus supporting previous suggestions that R. praetor is a species complex. Our findings demonstrate the potential of advanced morphological analyses in identifying separate species, contrary to the claims of morphological conservatism. Future analyses should combine geometric morphometrics with genetic analyses over the species range and include sub-fossil specimens from the Bismarck archipelago and Solomon Islands to resolve the evolutionary history of R. praetor.
Collapse
|
37
|
Barbosa S, Mestre F, White TA, Paupério J, Alves PC, Searle JB. Integrative approaches to guide conservation decisions: Using genomics to define conservation units and functional corridors. Mol Ecol 2018; 27:3452-3465. [PMID: 30030869 DOI: 10.1111/mec.14806] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 07/01/2018] [Accepted: 07/05/2018] [Indexed: 01/13/2023]
Abstract
Climate change and increasing habitat loss greatly impact species survival, requiring range shifts, phenotypic plasticity and/or evolutionary change for long-term persistence, which may not readily occur unaided in threatened species. Therefore, defining conservation actions requires a detailed assessment of evolutionary factors. Existing genetic diversity needs to be thoroughly evaluated and spatially mapped to define conservation units (CUs) in an evolutionary context, and we address that here. We also propose a multidisciplinary approach to determine corridors and functional connectivity between CUs by including genetic diversity in the modelling while controlling for isolation by distance and phylogeographic history. We evaluate our approach on a Near Threatened Iberian endemic rodent by analysing genotyping-by-sequencing (GBS) genomic data from 107 Cabrera voles (Microtus cabrerae), screening the entire species distribution to define categories of CUs and their connectivity: We defined six management units (MUs) which can be grouped into four evolutionarily significant units (ESUs) and three (putatively) adaptive units (AUs). We demonstrate that the three different categories of CU can be objectively defined using genomic data, and their characteristics and connectivity can inform conservation decision-making. In particular, we show that connectivity of the Cabrera vole is very limited in eastern Iberia and that the pre-Pyrenean and part of the Betic geographic nuclei contribute the most to the species genetic diversity. We argue that a multidisciplinary framework for CU definition is essential and that this framework needs a strong evolutionary basis.
Collapse
|
38
|
Ferreira CM, Sabino-Marques H, Barbosa S, Costa P, Encarnação C, Alpizar-Jara R, Pita R, Beja P, Mira A, Searle JB, Paupério J, Alves PC. Genetic non-invasive sampling (gNIS) as a cost-effective tool for monitoring elusive small mammals. EUR J WILDLIFE RES 2018. [DOI: 10.1007/s10344-018-1188-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
39
|
Sabino-Marques H, Ferreira CM, Paupério J, Costa P, Barbosa S, Encarnação C, Alpizar-Jara R, Alves PC, Searle JB, Mira A, Beja P, Pita R. Combining genetic non-invasive sampling with spatially explicit capture-recapture models for density estimation of a patchily distributed small mammal. EUR J WILDLIFE RES 2018. [DOI: 10.1007/s10344-018-1206-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
40
|
Frantz LAF, Rudzinski A, Nugraha AMS, Evin A, Burton J, Hulme-Beaman A, Linderholm A, Barnett R, Vega R, Irving-Pease EK, Haile J, Allen R, Leus K, Shephard J, Hillyer M, Gillemot S, van den Hurk J, Ogle S, Atofanei C, Thomas MG, Johansson F, Mustari AH, Williams J, Mohamad K, Damayanti CS, Wiryadi ID, Obbles D, Mona S, Day H, Yasin M, Meker S, McGuire JA, Evans BJ, von Rintelen T, Ho SYW, Searle JB, Kitchener AC, Macdonald AA, Shaw DJ, Hall R, Galbusera P, Larson G. Synchronous diversification of Sulawesi's iconic artiodactyls driven by recent geological events. Proc Biol Sci 2018; 285:rspb.2017.2566. [PMID: 29643207 PMCID: PMC5904307 DOI: 10.1098/rspb.2017.2566] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 03/16/2018] [Indexed: 11/13/2022] Open
Abstract
The high degree of endemism on Sulawesi has previously been suggested to have vicariant origins, dating back to 40 Ma. Recent studies, however, suggest that much of Sulawesi's fauna assembled over the last 15 Myr. Here, we test the hypothesis that more recent uplift of previously submerged portions of land on Sulawesi promoted diversification and that much of its faunal assemblage is much younger than the island itself. To do so, we combined palaeogeographical reconstructions with genetic and morphometric datasets derived from Sulawesi's three largest mammals: the babirusa, anoa and Sulawesi warty pig. Our results indicate that although these species most likely colonized the area that is now Sulawesi at different times (14 Ma to 2–3 Ma), they experienced an almost synchronous expansion from the central part of the island. Geological reconstructions indicate that this area was above sea level for most of the last 4 Myr, unlike most parts of the island. We conclude that emergence of land on Sulawesi (approx. 1–2 Myr) may have allowed species to expand synchronously. Altogether, our results indicate that the establishment of the highly endemic faunal assemblage on Sulawesi was driven by geological events over the last few million years.
Collapse
|
41
|
Hulme-Beaman A, Searle JB, Stockley P. Sperm competition as an under-appreciated factor in domestication. Biol Lett 2018; 14:rsbl.2018.0043. [PMID: 29563282 DOI: 10.1098/rsbl.2018.0043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 02/27/2018] [Indexed: 02/04/2023] Open
Abstract
Humans created an environment that increased selective pressures on subgroups of those species that became domestic. We propose that the domestication process may in some cases have been facilitated by changes in mating behaviour and resultant sperm competition. By adapting to sperm competition, proto-domestic animals could potentially have outcompeted their wild counterparts in human-constructed niches. This could have contributed to the restriction of gene flow between the proto-domesticates and their wild counterparts, thereby promoting the fixation of other domestication characteristics. Further to this novel perspective for domestication, we emphasize the general potential of postcopulatory sexual selection in the restriction of gene flow between populations, and urge more studies.
Collapse
|
42
|
Matveevsky SN, Pavlova SV, Atsaeva MM, Searle JB, Kolomiets OL. Dual mechanism of chromatin remodeling in the common shrew sex trivalent (XY 1Y 2). COMPARATIVE CYTOGENETICS 2017; 11:727-745. [PMID: 29114363 PMCID: PMC5672328 DOI: 10.3897/compcytogen.v11i4.13870] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
Here we focus on the XY1Y2 condition in male common shrew Sorex araneus Linnaeus, 1758, applying electron microscopy and immunocytochemistry for a comprehensive analysis of structure, synapsis and behaviour of the sex trivalent in pachytene spermatocytes. The pachytene sex trivalent consists of three distinct parts: short and long synaptic SC fragments (between the X and Y1 and between the X and Y2, respectively) and a long asynaptic region of the X in-between. Chromatin inactivation was revealed in the XY1 synaptic region, the asynaptic region of the X and a very small asynaptic part of the Y2. This inactive part of the sex trivalent, that we named the 'head', forms a typical sex body and is located at the periphery of the meiotic nucleus at mid pachytene. The second part or 'tail', a long region of synapsis between the X and Y2 chromosomes, is directed from the periphery into the nucleus. Based on the distribution patterns of four proteins involved in chromatin inactivation, we propose a model of meiotic silencing in shrew sex chromosomes. Thus, we conclude that pachytene sex chromosomes are structurally and functionally two different chromatin domains with specific nuclear topology: the peripheral inactivated 'true' sex chromosome regions (part of the X and the Y1) and more centrally located transcriptionally active autosomal segments (part of the X and the Y2).
Collapse
|
43
|
Prendergast ME, Buckley M, Crowther A, Frantz L, Eager H, Lebrasseur O, Hutterer R, Hulme-Beaman A, Van Neer W, Douka K, Veall MA, Quintana Morales EM, Schuenemann VJ, Reiter E, Allen R, Dimopoulos EA, Helm RM, Shipton C, Mwebi O, Denys C, Horton M, Wynne-Jones S, Fleisher J, Radimilahy C, Wright H, Searle JB, Krause J, Larson G, Boivin NL. Reconstructing Asian faunal introductions to eastern Africa from multi-proxy biomolecular and archaeological datasets. PLoS One 2017; 12:e0182565. [PMID: 28817590 PMCID: PMC5560628 DOI: 10.1371/journal.pone.0182565] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 07/20/2017] [Indexed: 02/02/2023] Open
Abstract
Human-mediated biological exchange has had global social and ecological impacts. In sub-Saharan Africa, several domestic and commensal animals were introduced from Asia in the pre-modern period; however, the timing and nature of these introductions remain contentious. One model supports introduction to the eastern African coast after the mid-first millennium CE, while another posits introduction dating back to 3000 BCE. These distinct scenarios have implications for understanding the emergence of long-distance maritime connectivity, and the ecological and economic impacts of introduced species. Resolution of this longstanding debate requires new efforts, given the lack of well-dated fauna from high-precision excavations, and ambiguous osteomorphological identifications. We analysed faunal remains from 22 eastern African sites spanning a wide geographic and chronological range, and applied biomolecular techniques to confirm identifications of two Asian taxa: domestic chicken (Gallus gallus) and black rat (Rattus rattus). Our approach included ancient DNA (aDNA) analysis aided by BLAST-based bioinformatics, Zooarchaeology by Mass Spectrometry (ZooMS) collagen fingerprinting, and direct AMS (accelerator mass spectrometry) radiocarbon dating. Our results support a late, mid-first millennium CE introduction of these species. We discuss the implications of our findings for models of biological exchange, and emphasize the applicability of our approach to tropical areas with poor bone preservation.
Collapse
|
44
|
Hatfield T, Barton N, Searle JB. A MODEL OF A HYBRID ZONE BETWEEN TWO CHROMOSOMAL RACES OF THE COMMON SHREW (SOREX ARANEUS
). Evolution 2017; 46:1129-1145. [DOI: 10.1111/j.1558-5646.1992.tb00624.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/1991] [Accepted: 01/04/1992] [Indexed: 11/28/2022]
|
45
|
Hauffe HC, Searle JB. EXTREME KARYOTYPIC VARIATION IN A MUS MUSCULUS DOMESTICUS
HYBRID ZONE: THE TOBACCO MOUSE STORY REVISITED. Evolution 2017; 47:1374-1395. [DOI: 10.1111/j.1558-5646.1993.tb02161.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/1992] [Accepted: 01/22/1993] [Indexed: 11/30/2022]
|
46
|
Honka J, Kvist L, Heikkinen ME, Helle P, Searle JB, Aspi J. Determining the subspecies composition of bean goose harvests in Finland using genetic methods. EUR J WILDLIFE RES 2017. [DOI: 10.1007/s10344-017-1077-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
47
|
Ballen CJ, Wieman C, Salehi S, Searle JB, Zamudio KR. Enhancing Diversity in Undergraduate Science: Self-Efficacy Drives Performance Gains with Active Learning. CBE LIFE SCIENCES EDUCATION 2017; 16:16/4/ar56. [PMID: 29054921 PMCID: PMC5749958 DOI: 10.1187/cbe.16-12-0344] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 07/03/2017] [Accepted: 07/11/2017] [Indexed: 05/18/2023]
Abstract
Efforts to retain underrepresented minority (URM) students in science, technology, engineering, and mathematics (STEM) have shown only limited success in higher education, due in part to a persistent achievement gap between students from historically underrepresented and well-represented backgrounds. To test the hypothesis that active learning disproportionately benefits URM students, we quantified the effects of traditional versus active learning on student academic performance, science self-efficacy, and sense of social belonging in a large (more than 250 students) introductory STEM course. A transition to active learning closed the gap in learning gains between non-URM and URM students and led to an increase in science self-efficacy for all students. Sense of social belonging also increased significantly with active learning, but only for non-URM students. Through structural equation modeling, we demonstrate that, for URM students, the increase in self-efficacy mediated the positive effect of active-learning pedagogy on two metrics of student performance. Our results add to a growing body of research that supports varied and inclusive teaching as one pathway to a diversified STEM workforce.
Collapse
|
48
|
Stojak J, McDevitt AD, Herman JS, Kryštufek B, Uhlíková J, Purger JJ, Lavrenchenko LA, Searle JB, Wójcik JM. Between the Balkans and the Baltic: Phylogeography of a Common Vole Mitochondrial DNA Lineage Limited to Central Europe. PLoS One 2016; 11:e0168621. [PMID: 27992546 PMCID: PMC5161492 DOI: 10.1371/journal.pone.0168621] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 12/02/2016] [Indexed: 11/30/2022] Open
Abstract
The common vole (Microtus arvalis) has been a model species of small mammal for studying end-glacial colonization history. In the present study we expanded the sampling from central and eastern Europe, analyzing contemporary genetic structure to identify the role of a potential 'northern glacial refugium', i.e. a refugium at a higher latitude than the traditional Mediterranean refugia. Altogether we analyzed 786 cytochrome b (cytb) sequences (representing mitochondrial DNA; mtDNA) from the whole of Europe, adding 177 new sequences from central and eastern Europe, and we conducted analyses on eight microsatellite loci for 499 individuals (representing nuclear DNA) from central and eastern Europe, adding data on 311 new specimens. Our new data fill gaps in the vicinity of the Carpathian Mountains, the potential northern refugium, such that there is now dense sampling from the Balkans to the Baltic Sea. Here we present evidence that the Eastern mtDNA lineage of the common vole was present in the vicinity of this Carpathian refugium during the Last Glacial Maximum and the Younger Dryas. The Eastern lineage expanded from this refugium to the Baltic and shows low cytb nucleotide diversity in those most northerly parts of the distribution. Analyses of microsatellites revealed a similar pattern but also showed little differentiation between all of the populations sampled in central and eastern Europe.
Collapse
|
49
|
Giménez MD, Förster DW, Jones EP, Jóhannesdóttir F, Gabriel SI, Panithanarak T, Scascitelli M, Merico V, Garagna S, Searle JB, Hauffe HC. A Half-Century of Studies on a Chromosomal Hybrid Zone of the House Mouse. J Hered 2016; 108:25-35. [PMID: 27729448 DOI: 10.1093/jhered/esw061] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 09/29/2016] [Indexed: 12/16/2022] Open
Abstract
The first natural chromosomal variation in the house mouse was described nearly 50 years ago in Val Poschiavo on the Swiss side of the Swiss-Italian border in the Central Eastern Alps. Studies have extended into neighboring Valtellina, and the house mice of the Poschiavo-Valtellina area have been subject to detailed analysis, reviewed here. The maximum extent of this area is 70 km, yet it has 4 metacentric races and the standard 40-chromosome telocentric race distributed in a patchwork fashion. The metacentric races are characterized by highly reduced diploid numbers (2n = 22-26) resulting from Robertsonian fusions, perhaps modified by whole-arm reciprocal translocations. The races hybridize and the whole Poschiavo-Valtellina area can be considered a "hybrid zone." The studies of this area have provided insights into origin of races within hybrid zones, gene flow within hybrid zones and the possibility of speciation in hybrid zones. This provides a case study of how chromosomal rearrangements may impact the genetic structure of populations and their diversification.
Collapse
|
50
|
Shipley JR, Campbell P, Searle JB, Pasch B. Asymmetric energetic costs in reciprocal-cross hybrids between carnivorous mice (Onychomys). ACTA ACUST UNITED AC 2016; 219:3803-3809. [PMID: 27688051 DOI: 10.1242/jeb.148890] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 09/25/2016] [Indexed: 01/07/2023]
Abstract
Aerobic respiration is a fundamental physiological trait dependent on coordinated interactions between gene products of the mitochondrial and nuclear genomes. Mitonuclear mismatch in interspecific hybrids may contribute to reproductive isolation by inducing reduced viability (or even complete inviability) due to increased metabolic costs. However, few studies have tested for effects of mitonuclear mismatch on respiration at the whole-organism level. We explored how hybridization affects metabolic rate in closely related species of grasshopper mice (genus Onychomys) to better understand the role of metabolic costs in reproductive isolation. We measured metabolic rate across a range of temperatures to calculate basal metabolic rate (BMR) and cold-induced metabolic rate (MRc) in O. leucogaster, O. torridus and O. arenicola, and in reciprocal F1 hybrids between the latter two species. Within the genus, we found a negative correlation between mass-specific BMR and body mass. Although O. arenicola was smaller than O. torridus, hybrids from both directions of the cross resembled O. arenicola in body mass. In contrast, hybrid BMR was strongly influenced by the direction of the cross: reciprocal F1 hybrids were different from each other but indistinguishable from the maternal species. In addition, MRc was not significantly different between hybrids and either parental species. These patterns indicate that metabolic costs are not increased in Onychomys F1 hybrids and, while exposure of incompatibilities in F2 hybrids cannot be ruled out, suggest that mitonuclear mismatch does not act as a primary barrier to gene flow. Maternal matching of BMR is suggestive of a strong effect of mitochondrial genotype on metabolism in hybrids. Together, our findings provide insight into the metabolic consequences of hybridization, a topic that is understudied in mammals.
Collapse
|