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Christine A. Nalepa - One of the best experts on this subject based on the ideXlab platform.
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Transcriptome sequencing and estimation of DNA methylation level in the subsocial wood-feeding cockroach Cryptocercus punctulatus (Blattodea: Cryptocercidae)
Applied Entomology and Zoology, 2017Co-Authors: Yoshinobu Hayashi, Christine A. Nalepa, Toru Miura, Kiyoto Maekawa, Shuji ShigenobuAbstract:The wood-feeding cockroach genus Cryptocercus is a subsocial and sister group of the eusocial cockroaches, i.e., termites. Although Cryptocercus is a key taxon for understanding the evolution of eusociality in the Blattodea (cockroaches and termites), few genetic resources are available for comparative genetic analyses. In this study, we conducted transcriptome sequencing of Cryptocercus punctulatus Scudder using next-generation sequencing technology to generate a massive genetic resource. By transcriptome sequencing and subsequent de novo transcriptome assembly, we obtained 132,191 contigs. The assembled transcriptome contained almost all of the conserved core eukaryote or insect genes. Furthermore, juvenile hormone- and DNA methylation-related genes that are considered to be key genes for the caste polyphenism in eusocial insects, were identified from the transcriptome assembly. In addition, the ratio of the observed (O) cytosine-phosphate-guanine (CpG) content to the expected (E) one (CpG O/E), which is a proxy for the DNA methylation level, was calculated for coding regions extracted from the assembly. The CpG O/E values were less than 1 in most of the coding regions, and the frequency distribution of the CpG O/E values was bimodal rather than unimodal. These results indicate that most C. punctulatus genes are involved in DNA methylation.
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distribution of karyotypes of the cryptocercus punctulatus species complex blattodea Cryptocercidae in great smoky mountains national park
Journal of Insect Science, 2017Co-Authors: Christine A. Nalepa, Keisuke Shimada, Kiyoto Maekawa, Peter LuykxAbstract:: During the period between 1999 and 2006, wood-feeding cockroaches in the Cryptocercus punctulatus Scudder species complex were collected throughout Great Smoky Mountains National Park, USA. The chromosome numbers of insects from 59 sites were determined, and phylogenetic analyses were performed based on mitochondrial COII and nuclear ITS2 DNA. The distribution of the three male karyotypes found in the park (2n = 37, 39, and 45) is mapped and discussed in relation to recent disturbances and glacial history. Clades of the three karyotype groups meet near the ridgeline separating North Carolina from Tennessee in the center of the park, suggesting that these may have originated from separate lower elevation refugia after the last glacial maximum. The timing of divergence and a significant correlation between elevation difference and genetic distance in two of the clades supports this hypothesis. The ecological role of the cockroaches in the park is discussed.
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parental social environment alters development of nutritionally independent nymphs in cryptocercus punctulatus dictyoptera Cryptocercidae
Behavioral Ecology and Sociobiology, 2016Co-Authors: Christine A. Nalepa, Consuelo ArellanoAbstract:Split-brood field studies using the biparental, subsocial wood-feeding cockroach Cryptocercus punctulatus indicate that parental absence in families of three different age classes of nutritionally independent juveniles results in significantly slower growth when compared to sib groups allowed to remain with adults, even when nymphs are more than 2 years old when parents are removed. In one family that was divided when nymphs were 15 months old and followed for 4 years after treatment, 69 % of nymphs allowed to remain with parents reached maturity in the third year of the study, while those isolated from parents remained in the subadult stage at the 3-year mark. In the fourth year, measurements of wet weights and head capsule widths of the newly mature adults in the two treatments of this family were not significantly different. A parental vs. non-parental social environment, then, resulted in different rates of growth to reproductive maturity, but nymphs in both treatments ultimately reached similar adult sizes. The results indicate that parental effects can modify offspring ontogeny independently of the direct transfer of resources in the form of trophallactic food and symbionts. Because cockroaches in this genus are sister group to the developmentally plastic and juvenilized termites, further exploration of the role of the social environment on development in Cryptocercus is warranted. Termites are eusocial cockroaches that exhibit weak or delayed post-embryonic development; the majority of colony members are arrested in the small, soft-bodied, altricial morphotype displayed by early juvenile stages of their subsocial sister group, Cryptocercus. Developmental dynamics in this cockroach genus can therefore provide insight into conditions that may have favored the origin of eusociality in the lineage. Here, we demonstrate that the parental social environment in Cryptocercus punctulatus modifies offspring development independently of the direct transfer of hindgut fluids and does so for more than 2 years after hatch. A system in which parent-offspring interactions modify juvenile ontogeny, whatever the mechanism, contributes to the unique set of circumstances that ultimately resulted in the evolution of termite eusociality.
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Surface Activity of the Xylophagous Cockroach Cryptocercus punctulatus (Dictyoptera: Cryptocercidae) Based on Collections from Pitfall Traps
Annals of the Entomological Society of America, 2011Co-Authors: Christine A. Nalepa, K. L. GraysonAbstract:Little information is available on the extra-log movement patterns of Cryptocercus punctulatus Scudder (Dictyoptera: Cryptocercidae), despite its key taxonomic position as a member of the xylophagous cockroach family that is sister group to termites. We conducted a field study in which individuals of C. punctulatus were collected from pitfall traps checked daily for 7 mo on the grounds of Mountain Lake Biological Station, VA. In total, 50 large nymphs, subadults, and adults of both sexes were captured, with adult activity strongest from midsummer through autumn. Surface activity seems unrelated to rainfall. The female-to-male sex ratio of trapped cockroaches was 2:1 overall and 1.5:1 in adults. Nymphs do not begin exploring outside of natal logs until they are at least half grown and significantly pigmented and sclerotized. Dissections of adult females indicated that more than half captured outside of logs (56%) had sperm in the spermatheca, and one female was carrying a spermatophore. These results suggest that sexual exclusivity cannot be assumed between paired individuals of this species.
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hatching asynchrony survivorship and development in young colonies of the subsocial cockroach cryptocercus punctulatus dictyoptera Cryptocercidae
Sociobiology, 2009Co-Authors: Christine A. Nalepa, Donald E MullinsAbstract:We report details of egg size and hatch, and neonate weight gain, development, and survivorship in field-collected families of the subsocialwood-feeding cockroach Cryptocercus punctulatus. Eggs are significantly smaller than those of other cockroaches, and hatch is asynchronous, with a span of three or more weeks between first and last-hatched nymphs in large broods. Dry weight of nymphs increases by more than an order of magnitude between the first and second instar. There is substantial early mortality, and nymphs in small families are developmentally more advanced than those in large families at the end of the natal year. Asynchronous hatch in C. punctulatus appears unrelated to the observed early mortality ofyoung nymphs; rather, a proportion of newly hatched offspring may routinely serve as walking trophic eggs in an environment where nitrogen is not easily obtained.
Srinivas Kambhampati - One of the best experts on this subject based on the ideXlab platform.
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Interspecific morphological variation in the wood-feeding cockroach, Cryptocercus (Dictyoptera: Cryptocercidae).
Arthropod structure & development, 2004Co-Authors: Benjamin T. Aldrich, Gregory Zolnerowich, Srinivas KambhampatiAbstract:Appalachian species of Cryptocercus (Dictyoptera: Cryptocercidae) display considerable genetic variation, but little morphological variation has been reported. We employed light and scanning electron microscopy to investigate variation in male and female reproductive structures among four species of Cryptocercus. Our results indicated consistent, species-specific differences exist in the genitalia of the four species. Males exhibit moderate interspecific differences in the shape of the subgenital plate and third left phallomere hook. Females display consistent interspecific differences in the size of setae on the basivalvula and great differences in size, number, and pattern of setae on the base of the second valves. Together, the interspecific variation in female reproductive structures can be used to identify each of the four Cryptocercus species that occur in the Appalachian Mountains.
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Species-Specific Allozyme Markers for Appalachian Wood-Feeding Cockroaches (Dictyoptera: Cryptocercidae)
Biochemical Genetics, 2004Co-Authors: Benjamin T. Aldrich, Elliot Krafsur, Srinivas KambhampatiAbstract:Members of the genus Cryptocercus are wood-feeding cockroaches that live in the temperate forests. Nine species are recognized in the genus worldwide: two in eastern Eurasia, two in China, and five in the United States. Within the United States, one species occurs in the Pacific Northwest and four occur in the Appalachian Mountains. Previous studies have revealed the presence of potential zones of overlap in distribution among the Appalachian species, raising the possibility of hybridization among them. Differences in mitochondrial DNA have previously been identified for the Appalachian species. However, to identify hybrid individuals one or more species-specific, codominant nuclear markers are required. Therefore, our objective was to undertake allozyme analysis of enzymatic loci to identify fixed, species-specific alleles for the four Appalachian species. We assayed a mean of 42 individuals each from 16 sites for allozyme variation for the four species. At 6 of the 33 loci examined, fixed alternate alleles were identified; a combination of 2 loci enabled the identification of all four species. To identify hybrids in the field, we examined 42 individuals each from 13 sites in which two or more of the above species occur in close proximity for presence of heterozygous individuals at one or more of the six fixed loci. No heterozygous individuals were found suggesting the lack of hybridization among the Appalachian species.
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phylogenetic analysis of blattabacterium endosymbiotic bacteria from the wood roach cryptocercus blattodea Cryptocercidae including a description of three new species
Molecular Phylogenetics and Evolution, 2003Co-Authors: Jeffrey W Clark, Srinivas KambhampatiAbstract:Abstract Members of the cockroach genus Cryptocercus are wood-feeding, subsocial insects that live in temperate forests of the Nearctic and Palaearctic. At present, nine species are recognized: Cryptocercus relictus and Cryptocercus kyebangensis in eastern Asia and Russia, Cryptocercus primarius and Cryptocercus matilei in southwestern China, Cryptocercus clevelandi in the western USA, and Cryptocercus darwini, Cryptocercus garciai, Cryptocercus punctulatus, and Cryptocercus wrighti in the eastern USA. Like all extant cockroaches, Cryptocercus harbor endosymbiotic bacteria, Blattabacterium, in their fat bodies. The endosymbionts in all cockroaches have been considered a single species, Blattabacterium cuenoti, since their discovery about a century ago. However, a recent analysis of DNA sequences from representatives of four cockroach families has indicated that there is considerable DNA sequence divergence among B. cuenoti from different host species. As a part of our studies on the evolution of Cryptocercus, we examined DNA sequence divergence among B. cuenoti from six of the nine known Cryptocercus species. Specifically, we sequenced ∼2400 bp of the 16S rRNA and 23S rRNA genes of B. cuenoti from six species of Cryptocercus. We found that B. cuenoti in Cryptocercus has differentiated into multiple monophyletic lineages distinguishable by DNA sequence of rRNA genes and host association. Our sequence divergence estimates were consistent with those reported for other, congeneric bacterial species. We propose the recognition of three new species of Blattabacterium within Cryptocercus species as follows: Blattabacterium relictus sp. nov. in C. relictus, Blattabacterium clevelandi sp. nov. in C. clevelandi, and Blattabacterium punctulatus sp. nov. in C. darwini, C. garciai, C. punctulatus, and C. wrighti.
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phylogeny of cryptocercus species blattodea Cryptocercidae inferred from nuclear ribosomal dna
Molecular Phylogenetics and Evolution, 2001Co-Authors: Shaon Hossain, Srinivas KambhampatiAbstract:The wood-feeding cockroaches of the genus Cryptocercus occur in temperate forests. Of the seven known species, five occur in the United States and two in Eurasia. Until 1997, all populations in the United States were considered a single species. Populations in the western United States were elevated to a species status based on variation in DNA sequence and morphology. In 1999, three new species were described from the eastern United States based on variation in chromosome number and mitochondrial DNA, bringing the number of species in the United States to five. The objective of this study was to determine if the DNA sequence of nuclear rRNA also signals the existence of four species in the eastern United States and to compare the inferred relationships with those proposed based on mitochondrial sequences. We obtained the DNA sequence from a portion of the 5.8S and 28S rRNA genes and the entire ITS2 region from 38 individuals and 30 additional clones to assess intraindividual, intraspecific, and interspecific variation. We found extensive sequence variation among the various species and little or no intraindividual and intraspecific variation. Phylogenetic analysis indicated the existence of monophyletic lineages among the eastern United States samples, which largely corresponded to the four species previously described. The inferred relationships were well-supported by bootstrap analysis and decay indices. Although the nuclear rRNA sequences resulted in a coherent phylogenetic tree, the ITS2 region contained many insertions and deletions, which may introduce homoplasy and ambiguity in alignment as more taxa are added to the data set.
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geographic distribution of and genetic variation in the wood roach cryptocercus dictyoptera Cryptocercidae in the united states
Annals of The Entomological Society of America, 2001Co-Authors: Brian Steinmiller, Srinivas Kambhampati, Brent L BrockAbstract:Members of the genus Cryptocercus are subsocial, xylophagous cockroaches that inhabit temperate forests of the Nearctic and Palaearctic. Seven species are recognized worldwide: five in the United States, and one each in Russia and China. Four (Cryptocercus darwini Burnside, Smith and Kambhampati, Cryptocercus garciai Burnside, Smith and Kambhampati, Cryptocercus punctulatus Scudder, Cryptocercus wrighti Burnside, Smith and Kambhampati) of the five species in the United States occur in the Appalachian Mountains and one (Cryptocercus clevelandi Byers) occurs in the Pacific Northwest. Previous studies have indicated that the distribution of the Appalachian species is allopatric; however, three of the four species occurred within a few kilometers of one another. Therefore, an intensive survey was undertaken in southwestern North Carolina and northern Georgia to determine if the species distributions are indeed allopatric or if there are zones of sympatry. With regard to C. clevelandi, previous studies have included samples from only a handful of locations in the western United States. Therefore, an extensive survey was undertaken in Oregon and California to map the geographic distribution of C. clevelandi and estimate genetic variation within and among populations. Our surveys indicated that three (C. darwini, C. garciai, C. wrighti) of the four Appalachian species have overlapping distributions in southwestern North Carolina and northern Georgia, a finding that raises the possibility of the existence of hybrid zones. Genetic variation among samples collected in Oregon and California indicated that, unlike the eastern United States, there is only one species of Cryptocercus in the western United States. In addition, we found that the distribution of C. clevelandi is considerably more patchy than that of the Appalachian species.
Zongqing Wang - One of the best experts on this subject based on the ideXlab platform.
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chromosome number diversity in asian cryptocercus blattodea Cryptocercidae and implications for karyotype evolution and geographic distribution on the western sichuan plateau
Systematics and Biodiversity, 2019Co-Authors: Lili Wang, Zongqing Wang, Shuran Liao, Minglun Liu, Wenbo Deng, Yanli CheAbstract:Cryptocercus cockroaches are remarkable for their similarity in external morphology while having a diversity in chromosome numbers. Most species are therefore delimited by karyotyping combined with...
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exploring the diversity of asian cryptocercus blattodea Cryptocercidae species delimitation based on chromosome numbers morphology and molecular analysis
Invertebrate Systematics, 2018Co-Authors: Lili Wang, Zongqing Wang, Nathan LoAbstract:Woodroaches from the genus Cryptocercus Scudder, 1862 are known to display low levels of morphological divergence, yet significant genetic divergence and variability in chromosome number. Compared with Cryptocercus taxa from North America, the diversity of the genus in Asia has received relatively little attention. We performed morphological and karyotypic examinations of multiple taxa from several previously unsampled mountainous areas of central and south-western China, and identified nine candidate species primarily on the basis of chromosome number. We then investigated diversity across all Asian Cryptocercus, through phylogenetic analyses of 135 COI sequences and 74 28S rRNA sequences from individuals of 28 localities, including species delimitation analysis in General Mixed Yule Coalescent (GMYC) and Automatic Barcode Gap Discovery (ABGD). Phylogenetic results indicated that individuals from the same locality constituted well supported clades. The congruence of GMYC and ABGD results were in almost perfect accord, with 28 candidate species described on the basis of karyotypes (including the nine identified in this study). We provide evidence that each valley population in the Hengduan Mountains contains a separate evolving lineage. We conclude that the principal cause of the rich Cryptocercus diversity in China has been the uplift of the Qinghai-Tibet Plateau.
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The Complete Mitogenome of the Wood-Feeding Cockroach Cryptocercus meridianus (Blattodea: Cryptocercidae) and Its Phylogenetic Relationship among Cockroach Families
International Journal of Molecular Sciences, 2017Co-Authors: Weijun Li, Zongqing WangAbstract:In this study, the complete mitochondrial genome of Cryptocercus meridianus was sequenced. The circular mitochondrial genome is 15,322 bp in size and contains 13 protein-coding genes, two ribosomal RNA genes (12S rRNA and 16S rRNA), 22 transfer RNA genes, and one D-loop region. We compare the mitogenome of C. meridianus with that of C. relictus and C. kyebangensis. The base composition of the whole genome was 45.20%, 9.74%, 16.06%, and 29.00% for A, G, C, and T, respectively; it shows a high AT content (74.2%), similar to the mitogenomes of C. relictus and C. kyebangensis. The protein-coding genes are initiated with typical mitochondrial start codons except for cox1 with TTG. The gene order of the C. meridianus mitogenome differs from the typical insect pattern for the translocation of tRNA-SerAGN, while the mitogenomes of the other two Cryptocercus species, C. relictus and C. kyebangensis, are consistent with the typical insect pattern. There are two very long non-coding intergenic regions lying on both sides of the rearranged gene tRNA-SerAGN. The phylogenetic relationships were constructed based on the nucleotide sequence of 13 protein-coding genes and two ribosomal RNA genes. The mitogenome of C. meridianus is the first representative of the order Blattodea that demonstrates rearrangement, and it will contribute to the further study of the phylogeny and evolution of the genus Cryptocercus and related taxa.
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reconstructing the phylogeny of blattodea robust support for interfamilial relationships and major clades
Scientific Reports, 2017Co-Authors: Zongqing Wang, Nathan LoAbstract:Cockroaches are among the most recognizable of all insects. In addition to their role as pests, they play a key ecological role as decomposers. Despite numerous studies of cockroach phylogeny in recent decades, relationships among most major lineages are yet to be resolved. Here we examine phylogenetic relationships among cockroaches based on five genes (mitochondrial 12S rRNA, 16S rRNA, COII; nuclear 28S rRNA and histone H3), and infer divergence times on the basis of 8 fossils. We included in our analyses sequences from 52 new species collected in China, representing 7 families. These were combined with data from a recent study that examined these same genes from 49 species, resulting in a significant increase in taxa analysed. Three major lineages, Corydioidea, Blaberoidea, and Blattoidea were recovered, the latter comprising Blattidae, Tryonicidae, Lamproblattidae, Anaplectidae, Cryptocercidae and Isoptera. The estimated age of the split between Mantodea and Blattodea ranged from 204.3 Ma to 289.1 Ma. Corydioidea was estimated to have diverged 209.7 Ma (180.5–244.3 Ma 95% confidence interval [CI]) from the remaining Blattodea. The clade Blattoidea diverged from their sister group, Blaberoidea, around 198.3 Ma (173.1–229.1 Ma). The addition of the extra taxa in this study has resulted in significantly higher levels of support for a number of previously recognized groupings.
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The Wood-Feeding Genus Cryptocercus (Blattodea: Cryptocercidae), with Description of Two New Species Based on Female Genitalia
Florida Entomologist, 2015Co-Authors: Zongqing Wang, Yang Li, Jin-jun WangAbstract:Two new Chinese Cryptocercus (Blattodea: Cryptocercidae) species, C. arcuatus sp. nov. and C. convexus sp. nov., are described together with photographs. This description includes the external structure of the adults and structures of the female genitalia. A comparative study of female genitalia was based on the 5 Chinese species in the family Cryptocercidae. Significant differences in female genitalia of Cryptocercidae are summarized. A key to these 5 species and a checklist of the species of Cryptocercus worldwide are provided.
Reinhard Predel - One of the best experts on this subject based on the ideXlab platform.
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A proteomic approach for studying insect phylogeny: CAPA peptides of ancient insect taxa (Dictyoptera, Blattoptera) as a test case
BMC Evolutionary Biology, 2009Co-Authors: Steffen Roth, Gerd Gade, Bastian Fromm, Reinhard PredelAbstract:Background Neuropeptide ligands have to fit exactly into their respective receptors and thus the evolution of the coding regions of their genes is constrained and may be strongly conserved. As such, they may be suitable for the reconstruction of phylogenetic relationships within higher taxa. CAPA peptides of major lineages of cockroaches (Blaberidae, Blattellidae, Blattidae, Polyphagidae, Cryptocercidae) and of the termite Mastotermes darwiniensis were chosen to test the above hypothesis. The phylogenetic relationships within various groups of the taxon Dictyoptera (praying mantids, termites and cockroaches) are still highly disputed. Results Tandem mass spectrometry of neuropeptides from perisympathetic organs was used to obtain sequence data of CAPA peptides from single specimens; the data were analysed by Maximum Parsimony and Bayesian Interference. The resulting cladograms, taking 61 species into account, show a topology which is in general agreement with recent molecular and morphological phylogenetic analyses, including the recent phylogenetic arrangement placing termites within the cockroaches. When sequence data sets from other neuropeptides, viz. adipokinetic hormones and sulfakinins, were included, the general topology of the cladogram did not change but bootstrap values increased considerably. Conclusion This study represents the first comprehensive survey of neuropeptides of insects for solely phylogenetic purposes and concludes that sequences of short neuropeptides are suitable to complement molecular biological and morphological data for the reconstruction of phylogenetic relationships.
Nathan Lo - One of the best experts on this subject based on the ideXlab platform.
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exploring the diversity of asian cryptocercus blattodea Cryptocercidae species delimitation based on chromosome numbers morphology and molecular analysis
Invertebrate Systematics, 2018Co-Authors: Lili Wang, Zongqing Wang, Nathan LoAbstract:Woodroaches from the genus Cryptocercus Scudder, 1862 are known to display low levels of morphological divergence, yet significant genetic divergence and variability in chromosome number. Compared with Cryptocercus taxa from North America, the diversity of the genus in Asia has received relatively little attention. We performed morphological and karyotypic examinations of multiple taxa from several previously unsampled mountainous areas of central and south-western China, and identified nine candidate species primarily on the basis of chromosome number. We then investigated diversity across all Asian Cryptocercus, through phylogenetic analyses of 135 COI sequences and 74 28S rRNA sequences from individuals of 28 localities, including species delimitation analysis in General Mixed Yule Coalescent (GMYC) and Automatic Barcode Gap Discovery (ABGD). Phylogenetic results indicated that individuals from the same locality constituted well supported clades. The congruence of GMYC and ABGD results were in almost perfect accord, with 28 candidate species described on the basis of karyotypes (including the nine identified in this study). We provide evidence that each valley population in the Hengduan Mountains contains a separate evolving lineage. We conclude that the principal cause of the rich Cryptocercus diversity in China has been the uplift of the Qinghai-Tibet Plateau.
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reconstructing the phylogeny of blattodea robust support for interfamilial relationships and major clades
Scientific Reports, 2017Co-Authors: Zongqing Wang, Nathan LoAbstract:Cockroaches are among the most recognizable of all insects. In addition to their role as pests, they play a key ecological role as decomposers. Despite numerous studies of cockroach phylogeny in recent decades, relationships among most major lineages are yet to be resolved. Here we examine phylogenetic relationships among cockroaches based on five genes (mitochondrial 12S rRNA, 16S rRNA, COII; nuclear 28S rRNA and histone H3), and infer divergence times on the basis of 8 fossils. We included in our analyses sequences from 52 new species collected in China, representing 7 families. These were combined with data from a recent study that examined these same genes from 49 species, resulting in a significant increase in taxa analysed. Three major lineages, Corydioidea, Blaberoidea, and Blattoidea were recovered, the latter comprising Blattidae, Tryonicidae, Lamproblattidae, Anaplectidae, Cryptocercidae and Isoptera. The estimated age of the split between Mantodea and Blattodea ranged from 204.3 Ma to 289.1 Ma. Corydioidea was estimated to have diverged 209.7 Ma (180.5–244.3 Ma 95% confidence interval [CI]) from the remaining Blattodea. The clade Blattoidea diverged from their sister group, Blaberoidea, around 198.3 Ma (173.1–229.1 Ma). The addition of the extra taxa in this study has resulted in significantly higher levels of support for a number of previously recognized groupings.