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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Sex-differentiation in the viviparous teleost "Xiphophorus helleri" Heckel ...

Essenberg, Jacob Martin, January 1900 (has links)
Thesis (Ph. D.)--University of Chicago, 1922. / "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." "Reprinted from Biological bulletin, vol. XLV, no. I, July, 1923." Bibliography: p. 75-77. Also available on the Internet.
2

A study of testis and ovary grafts on the hen's egg and their effects on the embryo ...

Minoura, Tadachika, January 1900 (has links)
Thesis (Ph. D.)--University of Chicago, 1922. / Letterpress descriptive of opposite plate on verso of each plate. "Author's abstract of this paper issued by the [Wistar institute] Bibliographic service, March 14." Stamped on t.p.: Private edition, distributed by the University of Chicago libraries, Chicago, Illinois. "Reprinted from the Journal of experimental zoölogy, vol. 33, no. 1, May, 1921." "Literature cited": p. 40-41. Also available on the Internet.
3

Molecular mechanism of SRY action during testicular differentiation in the mouse

Tavallaee, Ghazaleh. January 2007 (has links)
SRY (Sex determining Region of Y chromosome) is the master gene initiating testis determination in mammals. To shed light on the molecular mechanism of SRY action during testicular differentiation, we examined the effects of TAT-HMG fusion protein on gonadal sex differentiation in culture. HMG is the DNA binding motif of SRY and "TAT" is a protein transduction domain. Each pair of CD1 mouse gonadal primordia at 11.5 days post coitum (dpc) was cultured with or without TAT-HMG dissolved in dimethyl sulfoxide (DMSO) up to 3 days. Immunocytochemical labeling and Real-time RT-PCR of Sry, Sox9 and Mis indicated that DMSO blocked testicular differentiation, Sertoli cell differentiation and testis cords formation, downstream of SRY. TUNEL showed a massive mesenchymal cell death, which might be responsible for disruption of testis cord formation. Treatment with TAT-HMG rescued Sertoli cell differentiation, probably by up regulation of Sry, but not testis cord formation or cell death.
4

Molecular mechanism of SRY action during testicular differentiation in the mouse

Tavallaee, Ghazaleh. January 2007 (has links)
No description available.
5

The development of female- and male-oriented partner preference in the male laboratory rat indication for the organizational role of gonadal hormones /

Henley, Casey Leigh. January 2008 (has links)
Thesis (Ph. D.)--Michigan State University. Zoology , 2008. / Title from PDF t.p. (Proquest, viewed on Aug. 17, 2009) Includes bibliographical references (p. 146-161).
6

The role of activin system during gonad growth in black porgy (Acanthopagrus schlegeli): the interplay in bisexual gonad mediate by activin system through brain-pituitary-gonad axis

Chung, Yi-jou 25 July 2011 (has links)
Inhibin and activin are disulphide-linked dimeric proteins that belong to the transforming growth factor superfamily. Inhibin and activin are identified that they have ability to modulate the secretion of follicle-stimulating hormone, FSH, from pituitary. Activin can stimulate FSH secretion, on the other hand, inhibin can inhibit FSH production. According to many researches, inhibin and activin play an important roles in regulation of reproduction. Black porgy (Acanthopagrus schlegeli) is belong to protandry.that has a complex regulation in sex differentiation and development. The male differentiation in black porgy started at fourth month, and the testis become mature when the spawing season coming.in the first two year in black porgy, they are differentiate to functional males, and some of them will change to females in the third year. The objectives were to study the possible roles of inhibin¡Bactivin subunits and their receptors in sex differentiation and sex change in black porgy. The gene expression of activin system increase during the period of ovarian development. The expression of activin receptors in ovarian tissue are higher than in testis tissue in the testis-excision experiment. The expression of inhbab ¡Bacvr1and acvr2b after testis-excision are higher than in control in black porgy forebrain. The expression of inhbaa increase at four to five months after hatching in 0+-yr old black porgy, and the expression of inhbb and receptors decrease at the same time. According to these results, activin system may involve in the ovarian development and mature, and play important roles in testis differentiation and development in black porgy. Furthermore, activin system have sex dimorphisms in forebrain in black porgy.
7

Evaluation of dietary phytochemicals on sex differentiation and growth in Nile tilapia (Oreochromis niloticus)

Rodriguez Montes de Oca, Gustavo Alejandro, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 125-144).
8

Ontogenèse des neurones à kisspeptine chez le rat : neurogénèse et cartographie spatio-temporelle de kisspeptine de l'embryogénèse à l'âge adulte / Ontogenesis of kisspeptin neurons in rat : neurogenesis and spatio-temporal cartographie of kisspeptin neurone from embryogenesis to adulthood

Crossard, Elodie 14 December 2011 (has links)
Le kisspeptine (kp) est un peptide, dérivé du gène kiss-1, jouant un rôle majeur dans le contrôle central de la fonction de reproduction en régulant la sécrétion du GnRH chez l’adulte mais également au cours du développement. Les neurones exprimant kiss-1 sont situés dans la région rostrale périventriculaire du 3ème ventricule (RP3V) et le noyau arqué (ARC). L’expression de kiss-1 est hautement régulée par les stéroides sexuels, positivement dans RP3V et négativement dans ARC. Ces deux populations de neurones à kp semblent avoir des rôles différents. Les neurones à kp du RP3V seraient impliqués dans la genèse du pic préovulatoire et ceux de l’ARC dans la régulation de la sécrétion pulsatile de GnRH.L’objectif de la thèse était de déterminer la période de neurogenèse des neurones à kp ainsi que les variations de l’expression de kiss-1 et de kp dans ces deux régions au cours des différentes phases du développement chez le rat mâle et femelle.Nos résultats ont permis de cibler les périodes clés de l’ontogenèse des neurones à kp en montrant 1) que les neurones à kp de l’ARC naissent sur une période étendue à partir du jour embryonnaire (E)12,5; 2) l’existence d’une sous- expression péri-natale du kp dans l’ARC indépendante du sexe; 3) la mise en place, en période néonatale, de différences sexuelles dans les niveaux d’expression et la distribution neuroanatomique du kp; 4) l’existence de régulations péri-pubertaires de kp, dépendantes du sexe et de la région ; 5) la présence de fibres à kp dans des régions hypothalamiques suggère un rôle de kp au-delà de la fonction de reproduction. / Kisspeptin (kp) is a neuropeptide, derived from the kiss-1 gene, which plays a key role in the central control of reproduction by regulating GnRH secretion in adult but also during development. Cells which express kiss-1 are localized in two distincts hypothalamic regions: the rostral peri-ventricular third ventricule area (RP3V) and the arcuate nucleus (ARC). Kiss-1 expression is highly regulated by sex steroids: positively in the RP3V and negatively in the ARC. RP3V kp neurons have been implicated in the pre-ovulatory GnRH surge whereas ARC kp neurons may predominantly act on GnRH secretion pulsatility. The aim of this PhD work was to determine the neurogenesis period of kp neurons and changes of kiss-1 and kp expression in both regions during different stages of development in rats. Our results highlight key periods of kp neurons ontogenesis and show that: 1) ARC kp neurons are born during an extended embryonic neurogenesis period starting at embryonic day (E) 12,5; 2) a sex independent down-regulation of kp occurs during peri-natal period; 3) sex difference in the expression level and neuroanatomique distribution of kp establishes during neo-natal period; 4) kp was regulated during peri-pubertal period in sex and region dependant manner; 5) kp-ir fibers are detected throughout the septo-hypothalamic continuum suggesting that kp could be implicated in other functions than reproductive function.
9

Avaliação do dimorfismo sexual por meio de estudo antropométrico em imagens por tomografia computadorizada de feixe cônicos / Evaluation of sexual dimorphism through anthropometric mandibular study on images by cone-beam computed tomography

Gamba, Thiago de Oliveira, 1977- 21 August 2018 (has links)
Orientador: Francisco Haiter Neto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-21T22:06:49Z (GMT). No. of bitstreams: 1 Gamba_ThiagodeOliveira_M.pdf: 1982337 bytes, checksum: 59e9e9eb3c74854ff87b24acbb1ed82a (MD5) Previous issue date: 2013 / Resumo: O objetivo no presente estudo foi verificar se medidas antropológicas realizadas em mandíbulas, por meio de imagem de Tomografia Computadorizada de feixe cônico (TCFC), podem detectar o dimorfismo sexual em uma população brasileira. Adicionalmente, criar uma fórmula, a partir destas medidas para determinação do sexo. Para isso, foi selecionada uma amostra de 159 imagens de TCFC de indivíduos de uma população brasileira (74 homens e 85 mulheres), com idade variando de 18 a 60 anos. As imagens foram analisadas por 5 avaliadores, que realizaram seis mensurações: comprimento do ramo mandibular em altura (CR), comprimento da base mandibular (CBM), menor comprimento do ramo mandibular em largura (MCR), ângulo goníaco (AG), distância intercondilar (DIC) e distância intergoníaca (DIG), em reconstruções 3D de TCFC. Após quinze dias, as mensurações foram repetidas com 25 % da amostra. Para análise estatística, foi aplicada a Correlação Intraclasse na avaliação intra e interexaminador, Análise de Variância (ANOVA) para comparação entre os valores médios das mensurações presentes e equações binárias de Regressão Logística foram criadas para determinação do sexo. As mensurações evidenciaram valores do sexo masculino superiores aos do feminino, exceto na variável MCR que não apresentou diferença estatisticamente significante entre os sexos. As medidas com maiores índices dimórficos foram: DIG, CR, DIC, e AG. Associando estas quatro medidas obteve-se uma precisão de 95,1% na determinação do sexo, assim, foi possível concluir que a fórmula desenvolvida no presente estudo pode ser utilizada para identificação do sexo na prática forense / Abstract: The aim of this study was to determine whether anthropological measurements taken in jaws through image cone beam CT (CBCT) could aid in detecting sexual dimorphism in a Brazilian population. Additionally, this study was aimed at creating a formula from these measurements for sex determination. Subjects (n=159) involved a Brazilian population (74 men and 85 women), aged 18-60 years. The CBCT images were analyzed by 5 reviewers, who performed six measurements in the analysis of sexual dimorphism: Ramus length (R-L); Gonion-gnathion length (G-G-L); Minimum ramus breadth (M-R-Br); Gonial angle (G-A); Bicondylar breadth (Bic-Br); and Bigonial breadth (Big-Br), reconstructions in 3D CBCT. The measurements were repeated with 25% of the sample 15 days after the first evaluation for statistical analysis, the intraclass correlation was used to evaluate intra- and inter-examiners, the Analysis of Variance (ANOVA) to compare the mean values and the binary logistic regression equations were created to determine the sex. The measurements showed higher values for males, except for M-R-Br, showing no statistically significant difference between genders. The measurements with the highest rates were dimorphic: Big-Br, R-L, Bic-Br and GA. When the four variables were associated, an accuracy of 95.1% in sex determination was observed. In conclusion, the formula developed in this study can be used for sexual differentiation in forensic settings / Mestrado / Radiologia Odontologica / Mestre em Radiologia Odontológica
10

Molecular mechanisms underlying steroid hormone action during sex determination in the red-eared slider turtle, Trachemys scripta elegans

Ramsey, Mary Elizabeth, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

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