Testicular descent as a prerequisite for the production of mature spermatozoa and normal external genitalia morphogenesis, and therefore facilitating copulation and internal fertilization, are essential developmental steps in reproduction of vertebrate species. Cryptorchidism, the failure of testis descent, and feminization of external genitalia in the male, usually in the form of hypospadias, ...

A new species of the genus Catocala Schrank, 1802, duda sp. n. is described from south-western China, Yunnan Province. The diagnostic comparison made with lara Bremer, 1861. Adults and male genitalia both are illustrated.

X-linked lissencephaly with ambiguous genitalia is a rare and recently described syndrome. We report a neonate presenting with the classical features of the syndrome which includes lissencephaly, agenesis of the corpus callosum, intractable epilepsy of neonatal onset, acquired microcephaly, and male genotype with ambiguous genitalia. The baby was managed aggressively with antiepileptics. Early ...

Aedes nummatus Edwards is redescribed and the adult habitus, female and male genitalia and larva are illustrated. Aedes pseudonummatus, new species, is described and the female habitus and genitalia are illustrated. These 2 species are placed in the subgenus Diceromyia Theobald, nuTfbrr&atuS being transferred from the subgenus Aedimorphus Theobald. A map shows the distribution of the above 2 sp...

Mammalian sex determination involves complex interacting networks of cellular and hormonal signals leading to the development of male or female phenotypes. Three main sequential processes are involved: first, the establishment of chromosomal sex at fecundation (genetic sex); second, the development of the undifferentiated gonad into either testes or ovaries (gonadal sex); and third, differentia...

Anomala huangjianbini sp. n. is described from Chongqing, Fujian, Guangxi, Hunan, and Sichuan of China. Habitus male genitalia new species A. vitalisi Ohaus, 1914 are illustrated for purposes comparison. A distribution map both also provided.

Animal genitalia often show distinct developmental and evolutionary relationships with other parts of the body. Morphological observations of 29 sexually dimorphic and monomorphic beetle species in 16 genera of families Scarabaeidae and Lucanidae, Coleoptera, in 53 locations revealed that male genitalia size was consistently and distinctly less variable than that of other body parts within the ...

Amusurgus (Usgmona) excavatus Liu, Shi et Zhou, sp. nov. (China, Fujian) is described and illustrated with the male genitalia. Photos of habitus and ecological habitat are also included.

Detailed morphological descriptions and illustrations are provided for the adult male and female, male genitalia, pupal, and larval stages of Anopheles (Anopheles) pseudopunctipennis Theobald, a major vector of human malaria in Central and South America. Taxonomic and related literature records, diagnostic features, distribution, and bionomics of the species are included. A neotype male for the...

The main factor influencing sex determination of an embryo is the sex-determining region Y (SRY), a master regulatory gene located on the Y chromosome. The presence of SRY causes the bipotential gonad to differentiate into a testis. However, some individuals carry a Y chromosome but are phenotypically female (46,XY females) or have a female karyotype but are phenotypically male (46,XX males). 4...