scholarly journals The large X-effect on secondary sexual characters and the genetics of variation in sex comb tooth number inDrosophila subobscura

2016 ◽  
Vol 7 (2) ◽  
pp. 533-540 ◽  
Author(s):  
Briana E. Mittleman ◽  
Brenda Manzano-Winkler ◽  
Julianne B. Hall ◽  
Katharine L. Korunes ◽  
Mohamed A. F. Noor
Keyword(s):  
Secondary Sexual Characters ◽  
Sex Comb ◽  
Tooth Number ◽  
Comb Tooth ◽  
Secondary Sexual

scholarly journals A Quantitative Genetic Analysis of Male Sexual Traits Distinguishing the Sibling Species Drosophila simulans and D. sechellia

Genetics ◽  
1999 ◽  
Vol 153 (4) ◽  
pp. 1683-1699 ◽  
Author(s):  
Stuart J Macdonald ◽  
David B Goldstein
Keyword(s):  
Genetic Analysis ◽  
Sibling Species ◽  
Reproductive Traits ◽  
Drosophila Simulans ◽  
Directional Selection ◽  
Posterior Lobe ◽  
Sex Comb ◽  
Tooth Number ◽  
Comb Tooth ◽  
Shape And Size

Abstract A quantitative trait locus (QTL) genetic analysis of morphological and reproductive traits distinguishing the sibling species Drosophila simulans and D. sechellia was carried out in a backcross design, using 38 markers with an average spacing of 8.4 cM. The direction of QTL effects for the size of the posterior lobe was consistent across the identified QTL, indicating directional selection for this trait. Directional selection also appears to have acted on testis length, indicating that sexual selection may have influenced many reproductive traits, although other forms of directional selection cannot be ruled out. Sex comb tooth number exhibited high levels of variation both within and among isofemale lines and showed no evidence for directional selection and, therefore, may not have been involved in the early speciation process. A database search for genes associated with significant QTL revealed a set of candidate loci for posterior lobe shape and size, sex comb tooth number, testis length, tibia length, and hybrid male fertility. In particular, decapentaplegic (dpp), a gene known to influence the genital arch, was found to be associated with the largest LOD peak for posterior lobe shape and size.

scholarly journals Genetic architecture of variation in sex-comb tooth number in Drosophila simulans

2006 ◽  
Vol 87 (2) ◽  
pp. 93-107 ◽  
Author(s):  
HARUKI TATSUTA ◽  
TOSHIYUKI TAKANO-SHIMIZU
Keyword(s):  
Interspecific Variation ◽  
Drosophila Simulans ◽  
Epistatic Interactions ◽  
The Third ◽  
Sex Comb ◽  
Tooth Number ◽  
Comb Tooth ◽  
Trait Locus ◽  
The Relationship ◽  
Mapping Populations

The sex comb on the forelegs of Drosophila males is a secondary sexual trait, and the number of teeth on these combs varies greatly within and between species. To understand the relationship between the intra- and interspecific variation, we performed quantitative trait locus (QTL) analyses of the intraspecific variation in sex-comb tooth number. We used five mapping populations derived from two inbred Drosophila simulans strains that were divergent in the number of sex-comb teeth. Although no QTLs were detected on the X chromosome, we identified four QTLs on the second chromosome and three QTLs on the third chromosome. While identification and estimated effects of the second-chromosome QTLs depend on genetic backgrounds, significant and consistent effects of the two third-chromosome QTLs were found in two genetic backgrounds. There were significant epistatic interactions between a second-chromosome QTL and a third-chromosome QTL, as well as between two second-chromosome QTLs. The third-chromosome QTLs are concordant with the locations of the QTLs responsible for the previously observed differences in sex-comb tooth number between D. simulans and D. mauritiana.

Relationships between body size and secondary sexual characters, and sperm characters in male Dolly Varden char (Salvelinus malma )

2016 ◽  
Vol 26 (3) ◽  
pp. 397-402 ◽  
Author(s):  
Toshiaki Yamamoto ◽  
Noritaka Hirohashi ◽  
Eiji Fujiwara ◽  
Tatsuya Suzuki ◽  
Hatsuna Maruta ◽  
...  
Keyword(s):  
Body Size ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Dolly Varden Char ◽  
Secondary Sexual Characters ◽  
Sperm Characters ◽  
Secondary Sexual

Differentiation of the sexual characters and onset of maturity in the males of the "red claw" crayfish, Cherax quadricarinatus (Von Martens, 1898) (Astacidea, Astacida, Parastacidae)

2010 ◽  
Vol 60 (2) ◽  
pp. 195-208 ◽  
Author(s):  
Laura Susana López Greco ◽  
Fernanda Jimena Vazquez
Keyword(s):  
Sexual Maturity ◽  
Vas Deferens ◽  
Developmental Stages ◽  
Stage I ◽  
Early Event ◽  
Cherax Quadricarinatus ◽  
Secondary Sexual Characters ◽  
Single Structure ◽  
Red Claw Crayfish ◽  
Secondary Sexual

AbstractThe differentiation of the male reproductive system, the copulatory structures, "red patch" and onset of sexual maturity were studied in Cherax quadricarinatus. For this characterization 353 males were observed, dissected and processed for histological analysis. Three developmental stages were identified. At stage I the testes are two parallel cords with a few lobes or acinii, connected medially by a short thin bridge (X-shape) and the vasa deferentia are straight transparent cords. In the second stage, more lobulated testes present an H-shape and the vas deferens begins to differentiate into three distinct regions: proximal, medial and distal. In the last stage testes are two parallel cords tending to fuse along their entire length and become a single structure. From this stage, the development of the "red patch" occurs and spermatophore formation is observed in the vas deferens giving it white colour. These primary and secondary sexual characters could indicate the onset of sexual maturity. The morphology of the copulatory structure is lobular at stage I and it differentiates into an elongated structure during stage II. This study shows that in C. quadricarinatus the differentiation of primary and secondary sexual characters of males starts simultaneously and very early in development (0.09-0.10g achieved nearly 1 month old) and that acquisition of sexual maturity is also an early event (6g achieved nearly 3 month old). The compared features within Astacidea and Decapoda and the possible applications in the analysis of phylogenetic relationships between different taxa are discussed.

scholarly journals A new species of Sybistroma Meigen, 1824 (Diptera: Dolichopodidae) from China

2020 ◽  
Vol 418 ◽  
pp. 1-8
Author(s):  
I. Ya. Grichanov ◽  
Keyword(s):  
New Species ◽  
Yunnan Province ◽  
Hind Femur ◽  
Secondary Sexual Characters ◽  
A New Species ◽  
Secondary Sexual

A new species Sybistroma genriki sp. n. from the Yunnan province of China is described. It belongs to S. incisa group of species, differing from other species in mostly yellow antenna with arista-like stylus much longer than postpedicel; postpedicel elongated, much longer than wide, acute apically; stylus apical, with dark and white apical swelling; lower postocular setae white; legs mostly yellow except mostly black mid and hind coxae and brown-black distal spot on hind femur. A key to 11 species from Sichuan and Yunnan is provided, based mainly on male secondary sexual characters. The known distribution of the dolichopodine genus Sybistroma Meigen, 1824, is briefly discussed.

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