نتایج جستجو برای: sex determination identification
تعداد نتایج: 846993 فیلتر نتایج به سال:
Purpose. Radiography is important in forensic odontology for the identification of humans. The maxillary sinus is the largest of the paranasal sinuses and first to develop. Sinus radiography has been used for identification of skeletal remains and determination of gender. Hence, the aim and objectives of the present study were to establish a new method for gender determination using maxillary s...
In Caenorhabditis elegans, sex determination and dosage compensation are coordinately controlled through a group of genes that respond to the primary sex determination signal. Here we describe a new gene, sdc-3, that also controls these processes. In contrast to previously described genes, the sex determination and dosage compensation activities of sdc-3 are separately mutable, indicating that ...
Arthropods exhibit a large variety of sex determination systems both at the chromosomal and molecular level. Male heterogamety, female heterogamety, and haplodiploidy occur frequently, but partially different genes are involved. Endosymbionts, such as Wolbachia, Cardinium,Rickettsia, and Spiroplasma, can manipulate host reproduction and sex determination. Four major reproductive manipulation ty...
The review deals with features of sex determination in vertebrates. The mechanisms of sex determination are compared between fishes, amphibians, reptilians, birds, and mammals. We focus on structural and functional differences in the role of sex-determining genes in different vertebrates. Special attention is paid to the role of estrogens in sex determination in nonmammalian vertebrates.
The sex-determination system of the unicellular green alga, Chlamydomonas reinhardtii, is governed by genes in the mating-type (MT) locus and entails additional genes located in autosomes. Gene expression is initiated by nitrogen starvation, and cells differentiate into plus or minus gametes within 6h. Reviewed is our current understanding of gametic differentiation and fertilization, initiatio...
Studies of sex allocation offer excellent opportunities for examining the constraints and limits on adaptation. A major topic of debate within this field concerns the extent to which the ability of individuals to adaptively manipulate their offspring sex ratio is determined by constraints such as the method of sex determination. We address this problem by comparing the extent of sex-ratio adjus...
Sex determination is an important developmental event in the life cycle of all sexually reproducing plants. Recent studies of sex determination in many plant species, from ferns to maize, have been fruitful in identifying the diversity of genetic and epigenetic factors that are involved in determining the sex of the flower or individual. In those species amenable to genetic analysis, significan...
Zygotically contributed ovo gene product is required for the survival of female germ cells in Drosophila melanogaster. Trans-allelic combinations of weak and dominant ovo mutations (ovoD) result in viable germ cells that appear to be partially transformed from female to male sexual identity. The O V O ” ~ mutation is partially suppressed by many Sex-lethal alleles that affect the soma, while th...
The sex of an individual may be defined in three different ways: a. The type of gonad present b. General anatomical appearance and psychological orientation c. Genetic factors as determined by the presence of the XX or XY chromosomes. If uniformity is absent or equivocal in these characteristics, the decision as to whether an individual should be classified as male or female is difficult and is...
Human sex determination is a fascinating topic, particularly at the level of molecular genetics, as it represents an excellent paradigm for mammalian organ development. Recent progress has seen the addition of several new pieces to this developmental jigsaw puzzle. In mammals, the Y chromosome is male determining, and encodes a gene referred to as TDF (testis-determining factor), which induces ...
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