scholarly journals Variation in Diapause Responses Between Geographic Populations of the Predator Geocoris punctipes (Heteroptera: Geocoridae)

Author(s):  
John R. Ruberson ◽  
Kenneth V. Yeargan ◽  
Blake L. Newton
2021 ◽  
pp. 1-9
Author(s):  
Chiao Kuwana ◽  
Hiroyuki Fujita ◽  
Masataka Tagami ◽  
Takanori Matsuo ◽  
Ikuo Miura

The sex chromosomes of most anuran amphibians are characterized by homomorphy in both sexes, and evolution to heteromorphy rarely occurs at the species or geographic population level. Here, we report sex chromosome heteromorphy in geographic populations of the Japanese Tago’s brown frog complex (2n = 26), comprising Rana sakuraii and R. tagoi. The sex chromosomes of R. sakuraii from the populations in western Japan were homomorphic in both sexes, whereas chromosome 7 from the populations in eastern Japan were heteromorphic in males. Chromosome 7 of R. tagoi, which is distributed close to R. sakuraii in eastern Japan, was highly similar in morphology to the Y chromosome of R. sakuraii. Based on this and on mitochondrial gene sequence analysis, we hypothesize that in the R. sakuraii populations from eastern Japan the XY heteromorphic sex chromosome system was established by the introduction of chromosome 7 from R. tagoi via interspecies hybridization. In contrast, chromosome 13 of R. tagoi from the 2 large islands in western Japan, Shikoku and Kyushu, showed a heteromorphic pattern of constitutive heterochromatin distribution in males, while this pattern was homomorphic in females. Our study reveals that sex chromosome heteromorphy evolved independently at the geographic lineage level in this species complex.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wei Wang ◽  
Chunyan Ma ◽  
Longling Ouyang ◽  
Wei Chen ◽  
Ming Zhao ◽  
...  

AbstractIn order to provide valuable guidelines for the conservation of germplasm of Lateolabrax maculatus, the genetic diversity and population structure analysis were evaluated for eight geographic populations along coastal regions of China, using 11 microsatellite DNA markers. The genetic parameters obtained showed that, eight populations can be clustered into two groups, the Northern group and the Southern group, concordant with their geographical positions. The UPGMA tree constructed according to the Nei’s genetic distance along with the structure analysis and discriminant analysis of principal component also supported this result. This might be explained by the geographic separation and the divergent environmental conditions among the populations. It's worth noting that, QD (Qingdao) population from northern area was assigned to the Southern group and showed a close genetic relationship and similar genetic constitution with the southern populations. We speculated that large scales of anthropogenic transportation of wild fries from QD populations to the southern aquaculture areas in history should be the primary cause. The populations from GY (Ganyu), RD (Rudong) and BH (Binhai) had higher genetic diversity and showed limited genetic exchange with other populations, indicating better conservation of the natural resources in these regions. All populations were indicated to have experienced bottleneck events in history.


Limnologica ◽  
2010 ◽  
Vol 40 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Qin Ma ◽  
Yi-Long Xi ◽  
Jin-Yan Zhang ◽  
Xin-Li Wen ◽  
Xian-Ling Xiang

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Sakie Kodama ◽  
Hiroka Fujimori ◽  
Hiroshi Hakoyama

Abstract Costly anti-predator traits tend to be expressed only in high-predation conditions. For the cyprinid fish genus Carassius, deeper body depth is more adaptive to avoid predation by gape-limited piscivorous fish, but it raises swimming costs. It is therefore predicted that the relative body depth will decrease when the prey fish has reached a size larger than the predator gape-size. This prediction was tested by allometric analysis of the relation between body depth and standard length of triploid asexual females of the Japanese crucian carp (Carassius auratus sspp.) sampled from 13 geographic populations. The overall allometric relation was not significantly different from isometry. The estimate of the common major-axis slope was close to 1 (near-isometry). The mean relative body depth differed significantly among populations. A significant positive correlation was found with the mean annual air temperature. The geographic variation suggests that local selection pressures vary. In conclusion, the hypothesis that larger fish will have lower body depth was not supported, perhaps indicating that deep body depth in large fish is adaptive for some reason other than defense against piscivorous fish.


2019 ◽  
Author(s):  
Huifang Guo ◽  
Na Wang ◽  
Hongtao Niu ◽  
Dongxiao Zhao ◽  
Zhichun Zhang

Abstract Background Co-infection of endosymbionts in the same host is ubiquitous, and the interactions of the most common symbiont Wolbachia with other symbionts, including Spiroplasma et al., in invertebrate organisms have received increasing attention. However, the interactions between Wolbachia and Arsenophonus, another widely distributed symbiont in nature, are poorly understood. We tested the co-infection of Wolbachia and Arsenophonus in different populations of Nilaparvata lugens and investigated whether co-infection affected the population size of the symbionts in their host. Results A significant difference was observed in the co-infection incidence of Wolbachia and Arsenophonus among 5 populations of N. lugens from China, with nearly half of the individuals in the Zhenjiang population harbouring the two symbionts simultaneously, and the rate of occurrence was significantly higher than that of the other 4 populations. The Arsenophonus density in the superinfection line was significantly higher only in the Maanshan population compared with that of the single-infection line. Differences in the density of Wolbachia and Arsenophonus were found in all the tested double-infection lines, and the dominant symbiont species varied with the population only in the Nanjing population, with Arsenophonus the overall dominant symbiont. Conclusions Wolbachia and Arsenophonus could coexist in N. lugens, and the co-infection incidence varied with the geographic populations. Antagonistic interactions were not observed between Arsenophonus and Wolbachia, and the latter was the dominant symbiont in most populations.


2000 ◽  
Vol 23 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Vera Margarete Scarpassa ◽  
Silvia Geurgas ◽  
Ana Maria L. Azeredo-Espin ◽  
Wanderli Pedro Tadei

In the present study, we have examined the variability in Anopheles nuneztovari mitochondrial DNA of three populations from the Brazilian Amazon and one from western Colombia (Sitronela), using four restriction endonucleases (BclI, ClaI, HindIII, SstI). The haplotype diversity (h) was slightly elevated in all populations (0.5000 to 0.6765), whereas the nucleotide diversity (pi) was lower in the Sitronela population (0.0029) and higher in populations from the Brazilian Amazon (0.0056 to 0.0098). The degree of sequence divergence (delta) estimated within the Brazilian Amazon and that in Sitronela (0.0329 to 0.0371) suggests that these geographic populations of A. nuneztovari may eventually constitute separate species. The low sequence divergence values among the three Brazilian Amazon populations (0.0012 to 0.0031) indicate that these populations are genetically similar. These results are consistent with those recently reported for allozymes of these same populations.


1991 ◽  
Vol 39 (3) ◽  
pp. 285 ◽  
Author(s):  
WS Osborne ◽  
JA Norman

Reproductive compatibility and population genetic structure were examined in the corroboree frog, Pseudophryne corroboree, a species restricted to montane and subalpine environments in south-eastern Australia. The species comprises three geographic populations, represented by two morphological forms. Hybridisation experiments showed that the allopatric populations are interfertile, although crosses between the Snowy Mountains population (southern form) and each of the two northern populations (northern form) resulted in a significantly higher number of tadpoles with growth abnormalities. An electrophoretic examination of metamorphlings indicated that there was considerable genetic divergence between the two forms, with several loci approaching fixation of alternate alleles. The Snowy Mountains population also had substantially reduced levels of genetic variation compared to the two northern populations. Although genetic distances generally correlate with geographic distance, the genetic differences between the northern and southern populations form a pronounced step, not explicable by geographic distance alone. These findings have taxonomic implications which should be taken into account when considering the conservation management of this uncommon species.


PLoS ONE ◽  
2016 ◽  
Vol 11 (2) ◽  
pp. e0149507 ◽  
Author(s):  
Fei Mi ◽  
Ying Zhang ◽  
Dan Yang ◽  
Xiaozhao Tang ◽  
Pengfei Wang ◽  
...  

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