Chromosomes, Sex-cells, and Evolution in a Mammal

Chromosomes, Sex-cells, and Evolution in a Mammal PDF Author: Phillip V. Tobias
Publisher:
ISBN:
Category : Chromosomes
Languages : en
Pages : 460

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Chromosomes, Sex-cells, and Evolution in a Mammal

Chromosomes, Sex-cells, and Evolution in a Mammal PDF Author: Phillip V. Tobias
Publisher:
ISBN:
Category : Chromosomes
Languages : en
Pages : 460

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Book Description


Chromosomes, Sex-cells and Evolution in a Mammal. Based Mainly on Studies of the Reproductive Glands of the Gerbil ...

Chromosomes, Sex-cells and Evolution in a Mammal. Based Mainly on Studies of the Reproductive Glands of the Gerbil ... PDF Author: South African Council for Scientific and Industrial Research (Pretoria)
Publisher:
ISBN:
Category :
Languages : en
Pages : 420

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Sex Chromosomes and Sex-Linked Genes

Sex Chromosomes and Sex-Linked Genes PDF Author: Susumu Ohno
Publisher: Springer Science & Business Media
ISBN: 3642881785
Category : Science
Languages : en
Pages : 201

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Book Description
Natural selection operates among individual organisms which differ in their genetic constitution. The degree of hereditary variability within a species is greatly enhanced by cross-fertilization. Indeed, the mechanism of sexual reproduction occurred very early in evolution, for it is seen today even in bacteria. In Escherichia coli, fertilization occurs by passage of the single chromosome from the male into the female bacterium (LEDERBERG, 1959). In multicellular organisms, the separation of germ from soma, and the production of haploid gametes became mandatory. The gametes were of two types. One, extremely mobile, was designed to seek out and penetrate the other, which loaded with nutrients, received the mobile gamete and intiated the development of a new individual. The foundation for true bisexuality was thus laid. In the primitive state of bisexuality, whether an individual is to be a sperm-producing male or an egg-producing female appears to be decided rather haphazardly. In the worm, Banelia viridis, the minute males are parasites in the female. Larvae that become attached to the proboscis of an adult female become males, while unattached larvae sink to the bottom and become females (BALTZER, 1935). The more sophisticated state of bisexuality was initiated by setting aside a particular pair of chromosomes for specialization and making either the male or the female a heterogametic sex. Sex chromosomes as we know them were thus born.

Chromosomes, sex-cells and evolution in a mammal, based mainly on studies of the reproductive glands of the gerbil and a new list of chromosome numbers of mammals

Chromosomes, sex-cells and evolution in a mammal, based mainly on studies of the reproductive glands of the gerbil and a new list of chromosome numbers of mammals PDF Author: Phillip Valentine Tobias
Publisher:
ISBN:
Category :
Languages : en
Pages : 420

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The Evolution of Sex Determination

The Evolution of Sex Determination PDF Author: Leo W. Beukeboom
Publisher:
ISBN: 0199657149
Category : Medical
Languages : en
Pages : 243

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Book Description
Sexual reproduction is a fundamental aspect of life. It is defined by the occurrence of meiosis and the fusion of two gametes of different sexes or mating types. Sex-determination mechanisms are responsible for the sexual fate and development of sexual characteristics in an organism, be it a unicellular alga, a plant, or an animal. In many cases, sex determination is genetic: males and females have different alleles or different genes that specify their sexual morphology. In animals, this is often accompanied by chromosomal differences. In other cases, sex may be determined by environmental (e.g. temperature) or social variables (e.g. the size of an organism relative to other members of its population). Surprisingly, sex-determination mechanisms are not evolutionarily conserved but are bewilderingly diverse and appear to have had rapid turnover rates during evolution. Evolutionary biologists continue to seek a solution to this conundrum. What drives the surprising dynamics of such a fundamental process that always leads to the same outcome: two sex types, male and female? The answer is complex but the ongoing genomic revolution has already greatly increased our knowledge of sex-determination systems and sex chromosomes in recent years. This novel book presents and synthesizes our current understanding, and clearly shows that sex-determination evolution will remain a dynamic field of future research. The Evolution of Sex Determination is an advanced, research level text suitable for graduate students and researchers in genetics, developmental biology, and evolution.

An Atlas of Mammalian Chromosomes

An Atlas of Mammalian Chromosomes PDF Author: Tao C. Hsu
Publisher: Springer Science & Business Media
ISBN: 1461298261
Category : Medical
Languages : en
Pages : 244

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Sex Chromosomes and Sex Determination in Vertebrates

Sex Chromosomes and Sex Determination in Vertebrates PDF Author: Alberto J. Solari
Publisher: CRC Press
ISBN: 9780849345715
Category : Nature
Languages : en
Pages : 340

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Book Description
The cloning of the SRY gene and the attainment of XX mice transgenic for the Sry gene opened a new era in research on sex determination. This book surveys current knowledge of sex chromosomes and sex determination in all vertebrate classes, relying on the restriction of genetic recombination in sex chromosomes as the unifying concept of this subject. The book's interdisciplinary approach integrates contributions from the fields of cytogenetics, molecular biology, developmental biology, and evolutionary genetics. A detailed treatment of the meiotic behavior of sex chromosomes is featured, and the entire text is supplemented by numerous schemes, drawings, and electron micrographs. The book will be valuable to general cytogeneticists, vertebrate zoologists, and veterinarian and medical practitioners interested in the foundations of sex determination and the current knowledge of sex chromosomes. It will also interest students in advanced undergraduate and graduate courses in these areas.

An Atlas of Mammalian Chromosomes

An Atlas of Mammalian Chromosomes PDF Author: Tao C. Hsu
Publisher: Springer
ISBN: 1461298245
Category : Medical
Languages : en
Pages : 190

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Animal Cytology and Evolution

Animal Cytology and Evolution PDF Author: Michael James Denham White
Publisher: CUP Archive
ISBN: 9780521070713
Category : Science
Languages : en
Pages : 976

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Book Description
Chromosomes as supermolecular systems; The mitotic mechanism in evolution Endomitosis and endopolyploidy; Giant chromosomes the polytene type; Giant chromosomes the lampbrush type; The mechanism of meiosis; Chromosomes rearrangements occourrence and mechanisms; Chromosomal polymorphism in natural populations; Supernumerary chromosomes; Chromosomal rearrangements and speciaton evolution of the meiotic mechanism. The evolution of aberrant genetic systems; The cytology of interspecific hybrid;. The evolution of sex determination; Haplodiploidy; Thelytoky.

Sex Determination in Vertebrates

Sex Determination in Vertebrates PDF Author:
Publisher: Academic Press
ISBN: 0128115041
Category : Science
Languages : en
Pages : 394

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Book Description
Sex Determination, Volume 134, the latest release in the Current Topics in Developmental Biology series, contains current reviews in the field of vertebrate sex determination. It covers molecular pathways of sex determination in genetic and environmental species and encompasses both sex determination of somatic lineages and commitment of germ cells to male or female fate. Chapters in this new release cover, amongst other topics, Mapping the Sox9 Enhancer Elements, Epigenetic Regulation of Sex Determination, Evolution and Management of Sex Chromosomes, Regulation of Germ Cell Sex Identity in Medaka, Control of Sex Determination in Zebrafish, Sexually Dimorphic Germ Cell Identity in Mammals, and more. Contains reviews written by leading experts in each field Includes informative figures that illustrate principle points that are useful for teaching Written in a style that is clear and simple