Exploring the diversity of Asian Cryptocercus (Blattodea : Cryptocercidae): species delimitation based on chromosome numbers, morphology and molecular analysis

2018 ◽  
Vol 32 (1) ◽  
pp. 69 ◽  
Author(s):  
Qikun Bai ◽  
Lili Wang ◽  
Zongqing Wang ◽  
Nathan Lo ◽  
Yanli Che

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.

2020 ◽  
Vol 13 (1) ◽  
pp. 196
Author(s):  
Mengmeng Meng ◽  
Weiguo Fan ◽  
Jianchang Lu ◽  
Xiaobin Dong ◽  
Hejie Wei

Qinghai-Tibet Plateau is a typical resource-rich but economically backward region in western China, and it is of great urgency to improve human well-being. Combined with previous scholars’ research and the characteristics of Qinghai-Tibet Plateau, this paper constructs an index system of human well-being including four dimensions: income and consumption, means of production, means of subsistence, and resource acquisition ability. Then, it uses generalized matrix method estimations to measure the influence of energy utilization and economic development on human well-being and makes a regression analysis on the influence of energy utilization and economic development on human well-being in various provinces in this region. It is found that per capita GDP and coke utilization promote the well-being of all dimensions, while the urban registered unemployment rate only promotes the well-being of means of subsistence. The utilization of gasoline and natural gas promotes income and consumption and inhibits the means of subsistence and resource acquisition ability, but they have opposite effects on means of production. The impacts of energy utilization and economic development in different provinces on human well-being are different. This study is of great significance to the related research aiming at improving people’s livelihood and promoting regional development.


2010 ◽  
Vol 60 (4) ◽  
pp. 449-465
Author(s):  
Wen Longying ◽  
Zhang Lixun ◽  
An Bei ◽  
Luo Huaxing ◽  
Liu Naifa ◽  
...  

AbstractWe have used phylogeographic methods to investigate the genetic structure and population history of the endangered Himalayan snowcock (Tetraogallus himalayensis) in northwestern China. The mitochondrial cytochrome b gene was sequenced of 102 individuals sampled throughout the distribution range. In total, we found 26 different haplotypes defined by 28 polymorphic sites. Phylogenetic analyses indicated that the samples were divided into two major haplogroups corresponding to one western and one eastern clade. The divergence time between these major clades was estimated to be approximately one million years. An analysis of molecular variance showed that 40% of the total genetic variability was found within local populations, 12% among populations within regional groups and 48% among groups. An analysis of the demographic history of the populations suggested that major expansions have occurred in the Himalayan snowcock populations and these correlate mainly with the first and the second largest glaciations during the Pleistocene. In addition, the data indicate that there was a population expansion of the Tianshan population during the uplift of the Qinghai-Tibet Plateau, approximately 2 million years ago.


2012 ◽  
Vol 55 (10) ◽  
pp. 1620-1626
Author(s):  
HuaZhou Yao ◽  
RenJie Zhang ◽  
JingGen Sha ◽  
JianXiong Wang ◽  
ZhiJun Niu ◽  
...  

Author(s):  
Caixin Yang ◽  
Yibo Bai ◽  
Kui Dong ◽  
Jing Yang ◽  
Xin-He Lai ◽  
...  

Four Gram-stain-positive, catalase-negative, non-spore-forming, rod-shaped bacterial strains (zg-325T, zg329, dk561T and dk752) were isolated from the respiratory tract of marmot (Marmota himalayana) and the faeces of Tibetan gazelle (Procapra picticaudata) from the Qinghai-Tibet Plateau of PR China. The results of 16S rRNA gene sequence-based phylogenetic analyses indicated that strains zg-325T and dk561T represent members of the genus Actinomyces , most similar to Actinomyces denticolens DSM 20671T and Actinomyces ruminicola B71T, respectively. The DNA G+C contents of strains zg-325T and dk561T were 71.6 and 69.3 mol%, respectively. The digital DNA–DNA hybridization values of strains zg-325T and dk561T with their most closely related species were below the 70 % threshold for species demarcation. The four strains grew best at 35 °C in air containing 5 % CO2 on brain heart infusion (BHI) agar with 5 % sheep blood. All four strains had C18:1ω9c and C16:0 as the major cellular fatty acids. MK-8 and MK-9 were the major menaquinones in zg-325T while MK-10 was predominant in dk561T. The major polar lipids included diphosphatidylglycerol and phosphatidylinositol. On the basis of several lines of evidence from phenotypic and phylogenetic analyses, zg-325T and dk561T represent novel species of the genus Actinomyces , for which the name Actinomyces marmotae sp. nov. and Actinomyces procaprae sp. nov. are proposed. The type strains are zg-325T (=GDMCC 1.1724T=JCM 34091T) and dk561T (=CGMCC 4.7566T=JCM 33484T). We also propose, on the basis of the phylogenetic results herein, the reclassification of Actinomyces liubingyangii and Actinomyces tangfeifanii as Boudabousia liubingyangii comb. nov. and Boudabousia tangfeifanii comb. nov., respectively.


2020 ◽  
Vol 70 (4) ◽  
pp. 2233-2238 ◽  
Author(s):  
Zhi Tian ◽  
Shan Lu ◽  
Dong Jin ◽  
Jing Yang ◽  
Ji Pu ◽  
...  

Two Gram-staining-positive, catalase-positive, oxidase-negative, aerobic, non-motile, irregular rod-shaped bacterial strains (Z350T and Z527) were isolated from intestinal contents of plateau pika (Ochotona curzoniae) from the Qinghai–Tibet Plateau, PR China. Results of phylogenetic analyses based on 16S rRNA gene sequences indicated that strain Z350T belongs to the genus Mumia (family Nocardioidaceae ) but clearly differs from the currently recognized species Mumia xiangluensis DSM 101040T (98.4 % similarity) and Mumia flava DSM 27763T (97.4 %). Strain Z350T had a DNA G+C content of 70.7 mol% and shared 80.4 and 76.7 % average nucleotide identity values and 23.4 and 20.6 % in silico DNA–DNA hybridization relatedness with M. xiangluensis DSM 101040T and M. flava DSM 27763T, respectively. Further phylogenetic analyses based on 497 core genes indicated that our isolates were members of the genus Mumia but separated from all existing genera within the family Nocardioidaceae . The major cellular fatty acids were C18 : 1 ω9c and 10-methyl C18 : 0. The cell wall contained ll-diaminopimelic acid as the diamino acid, and rhamnose, ribose and glucose as whole cell-wall sugars. MK-9(H4) was detected as the major menaquinone. Polar lipids present were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and one unidentified phospholipid. Based on distinct differences in the genotypic and phenotypic data from the two Mumia species, a novel species, Mumia zhuanghuii sp. nov., is proposed. The type strain is Z350T (=CGMCC 4.7464T=DSM 106288T).


2021 ◽  
Vol 9 ◽  
Author(s):  
Chunlin Chen ◽  
Wenjie Yang ◽  
Jianquan Liu ◽  
Zhenxiang Xi ◽  
Lei Zhang ◽  
...  

Distributional shifts driven by Quaternary climatic oscillations have been suggested to cause interspecific hybridization and introgression. In this study, we aimed to test this hypothesis by using population transcriptomes and coalescent modeling of two alpine none-sister gentians. Previous studies suggested that historical hybridizations occurred between Gentiana siphonantha and G. straminea in the high-altitude Qinghai-Tibet Plateau although both species are not sister to each other with the most recent divergence. In the present study, we sequenced transcriptomes of 33 individuals from multiple populations of G. siphonantha and G. straminea. The two species are well delimited by nuclear genomic SNPs while phylogenetic analyses of plastomes clustered one G. straminea individual into the G. siphonantha group. Further population structure analyses of the nuclear SNPs suggested that two populations of G. siphonantha were admixed with around 15% ancestry from G. straminea. These analyses suggested genetic introgressions from G. straminea to G. siphonantha. In addition, our coalescent-based modeling results revealed that gene flow occurred between the two species since Last Glacier Maximum after their initial divergence, which might have leaded to the observed introgressions. Our results underscore the significance of transcriptome population data in determining timescale of interspecific gene flow and direction of the resulting introgression.


2019 ◽  
Vol 186 (4) ◽  
pp. 892-914 ◽  
Author(s):  
Diana Delicado ◽  
Beatriz Arconada ◽  
Amanda Aguado ◽  
Marian A Ramos

Abstract Valvatiform gastropods of the family Hydrobiidae are frequently found in European spring-fed systems. Their simplified and sometimes convergent morphological structures and restricted geographical ranges make the description and identification of valvatiform species challenging. In the Iberian Peninsula, to date, 20 valvatiform species have been described morphologically. To test morphological species delimitations and to evaluate the role of physical geography on their evolutionary history, we analysed two mitochondrial (COI and 16S rRNA) and two nuclear (28S rRNA and 18S rRNA) gene fragments of 16 valvatiform species from the Iberian Peninsula. Molecular species delimitation methods consistently inferred 11 of the nominal species. Our phylogenetic analyses recovered the species Islamia azarum as an independent lineage, distantly related to other genera, which we place in the new genus Deganta. Furthermore, Iberian valvatiform hydrobiids do not form a monophyletic subunit, but they are included in two distinct clades of Hydrobiidae. Divergence times indicate that speciation in these clades is likely to have coincided with the formation of major Iberian mountain ranges and river basins. Similarities of geographical subdivision and divergent times between this assemblage and the non-valvatiform genus Corrosella provide strong evidence for the role of the Iberian geographical barriers in shaping the biogeography of these springsnails.


2016 ◽  
Vol 40 (6) ◽  
pp. 794-810 ◽  
Author(s):  
Jay Gao ◽  
Xilai Li

The frigid swampy meadows of the Qinghai–Tibet Plateau in western China have suffered widespread degradation. The severe degradation of such meadows can lead to the formation of a landscape commonly known as heitutan. Much research has been undertaken to study its triggers, formation mechanism, grading of severity, and rehabilitation. These studies are comprehensively reviewed in this paper. In particular, it attempts to reconcile two divergent theories on heitutan formation by proposing a new model to elucidate the role of a given factor at each stage of degradation. In this model, climate desiccation is the most important in transforming healthy meadow to dry grassland, while rodent attack is the most important in worsening dry grassland to degraded meadow. Overgrazing is the most important factor during the early stages of degradation. Wind and water erosion is important during the final stage, when a large quantity of loose materials has been accumulated by rodent burrowing. Also covered in this paper is how to rehabilitate heitutan to productive use, including the effectiveness of various measures. Finally, this paper identifies the gap in our understanding of swampy meadow degradation and spells out a future research agenda. It is concluded that future research on heitutan will undergo a transformation from descriptive to quantitative. The expected research outcome will inform herders of the appropriate strategies that can be adopted to prevent heitutan formation. This proactive approach will minimize economic loss from swampy meadow degradation and reduce its adverse impact on the environment.


Zootaxa ◽  
2019 ◽  
Vol 4623 (1) ◽  
pp. 113-131
Author(s):  
YU MEI ◽  
TAKEHIRO K. KATOH ◽  
JIAN-JUN GAO

The Hirtodrosophila melanderi species group is currently known for thirteen described species, most of which were thought to be fungivorous. More than half known species of this species group were recorded exclusively from high altitude zone to the southeast of the Qinghai-Tibet Plateau in China. In our recent field survey in the Huanglong National Nature Reserve (located to the east of the Qinghai-Tibet Plateau) in Sichuan Province, China, we collected dozens of specimens of the H. melanderi group there. In the present study, these specimens are subjected to species delimitation based on data of not only morphology, but also DNA barcodes (nucleotide sequences of a 658-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene). The five new species thus recognized are described: Hirtodrosophila minshanensis sp. nov., H. lambda sp. nov., H. zhangae sp. nov., H. zouae sp. nov., and H. nigrispina sp. nov. In addition, an updated key to all species of the H. melanderi species group is provided. 


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