Sex-determination system<

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Sexb> determinationb> in Hymenoptera

Regardless of such homologies, it seems clear that the sexb> determinationb> systems of the Hymenoptera reflect in many ways the peculiar life histories and conditions of individual species.
This information, which locates loci near the sexb> determining locus, sheds little light on sexb> determinationb>, but may be useful for future studies.
While in recent years evidence has mounted that a great number of biological pathways are conserved across the animal kingdom, one developmental process which for the most part has evaded this grand display of commonality is that of sexb> determinationb>, which in contrast seems to have evolved rather rapidly (Marín and Baker, 1998).

http://www.sccs.swarthmore.edu/users/99/mahowald/hymenoptera.html (4726 words)



Sexb> Determinationb>

It seems likely that the sexb> determinationb> pathway will be related to that of Drosophila melanogaster subsequent to the action of the sexlethal gene, which does not appear to be involved in sexb> determinationb> in other groups of Diptera (Martin & Lee 1999).
Martin, J. Interrelation of inversion systems in the midge Chironomus intertinctus (Diptera: Nematocera) I. A sexb>-linked inversion.
A similar MD system probably also occurs in other Nematocera, such as mosquitoes and blackflies, and may even extend to some of the higher Diptera.

http://www.genetics.unimelb.edu.au/Martin2/sexdt.html (690 words)



Conservation of the global sexb> determinationb> gene tra-1 in distantly related nematodes -- Pires-daSilva and Sommer 18 (10): 1198 -- Genes and Development

Wilkins, A.S. Moving up the hierarchy: A hypothesis on the evolution of a genetic sexb> determinationb> pathway.
Schedl, T., Graham, P.L., Barton, M.K., and Kimble, J. Analysis of the role of tra-1 in germline sexb> determinationb> in the nematode Caenorhabditis elegans.
To study the evolution of sexb> determinationb> pathways

http://www.genesdev.org/cgi/content/full/18/10/1198 (5300 words)



Sexy splicing: regulatory interplays governing sexb> determinationb> from Drosophila to mammals -- Lalli et al. 116 (3): 441 -- Journal of Cell Science

One of the organisms in which the sexb> determinationb> pathway
critical roles in the sexb> determinationb> process and are subject
Wilkins, A. Moving up the hierarchy: a hypothesis on the evolution of a genetic sexb> determinationb> pathway.

http://jcs.biologists.org/cgi/content/full/116/3/441 (2962 words)



Exploring the Envelope: Systematic Alteration in the Sexb>-Determinationb> System of the Nematode Caenorhabditis elegans -- Hodgkin 162 (2): 767 -- Genetics

or sexb> determinationb> in response to nutritional conditions,
, J., 1986 Sexb> determinationb> in the nematode Caenorhabditis elegans: analysis of tra-3 suppressors and characterization of fem genes.
Maternal sexb> determinationb> by the autosomal gene tra-3:

http://www.genetics.org/cgi/content/full/162/2/767 (7245 words)



Ch21.doc

In addition to the primary sexb> organs that produce and carry gametes, many vertebrates develop secondary sexb> characteristics that are important in sexb> recognition, as signals of sexual maturity and receptivity, in courtship behavior, and sometimes in combat among males for access to females (Fig.
The environmental condition in which the eggs develop is an important determinant of sexb> in many other vertebrates.
The male sexb> hormones are cortical androgen, produced by the adrenal cortex, and testosterone, produced by the interstitial cells of the testis; the female hormones are estrogen and progesterone, secreted by the ovarian follicles and corpora lutea.

http://www.bio.umass.edu/biology/bemis/FAOV4/Ch21.doc (7245 words)



Sexb> determinationb> of Cannabis - Genetic, environmental, or both? - Marijuana Growing

All sexb>-determinationb> systems are enzyme/hormone/chemically controlled, but the triggering mechanisms for the determinationb> systems vary from purely chromosome-controlled to purely environmental.
The genetic-afficionado's approach is that it is determined at pollination, and they base their arguements on the human and mammal XX/XY chromosome-determinationb> system.
Some species have their sexb> determined by bacterial infections, and others again practice sexb>-changes, where they start out as one gender and changes sexb> during their lifetime.

http://www.overgrow.com/edge/showthread/t-466228.html (7245 words)



RNA Binding Protein Sexb>-Lethal (Sxl) and Control of Drosophila Sexb> Determinationb> and Dosage Compensation -- Penalva and Sánchez 67 (3): 343 -- Microbiology and Molecular Biology Reviews

The X:A signal and the control of sexb> determinationb>, sexual behavior, and dosage compensation.
that affect the sexb> determinationb> process without affecting
The WT1 gene is implicated in mammalian sexb> determinationb>, and

http://mmbr.asm.org/cgi/content/full/67/3/343 (8999 words)



1001.txt

The hermaphrodite condition appears to result from the modification of a basic male/female sexb>-determinationb> system, which permits both spermatogenesis and oogenesis to occur within a female soma.
The relative expression of these five genes was determined by measuring the efficiencies of suppressers against amber mutations in genes affecting the nervous system, hypodermis, muscle, and sexb> determinationb>.
Both somatic and germline aspects of sexb> determinationb> are affected.

http://biosci.umn.edu/CGC/Bibliography/1001.txt (8999 words)



SWA3Sex.doc

Many other organisms have environmental sexb> determinationb> (ESD).
Some species of fish, for example, are sequential hermaphrodites that change their sexb> one or more times over the course of their lifetime.
Sexb> in these species is determined by fertilization: fertilized eggs develop into diploid females, and unfertilized eggs develop into haploid males.

http://webpub.alleg.edu/dept/bio/bio340/SWA/SWA3Sex.doc (519 words)



Sexb>-determinationb> system - Hutchinson encyclopedia article about Sexb>-determinationb> system

Most fish have a very flexible system of sexb> determinationb>, which can be affected by external factors.
For example, in wrasse all individuals develop into females, but the largest individual in each area or school changes sexb> to become the local breeding male.
Process by which the sexb> of an organism is determined.

http://encyclopedia.farlex.com/Sex-determination+system (277 words)



MCDB 2150 -- Lecture 11

XY males are hemizygous: One of the features of an X/Y sexb> chromosome system is that females have two copies of the X chromosome, one of which is inherited from each parent, whereas males have only one, inherited from the mother, and paired with a Y chromosome inherited from the father.
Patterns of inheritance: In this lecture, we will focus primarily on patterns of inheritance in the XX/XY system in mammals, including humans, and in Drosophila, with some brief references to other systems.
However, individuals of both sexes normally express low levels of the hormones associated primarily with the other sexb>, and cases can be found within the usually accepted range of normalcy where there is some degree of expression of facial hair in women or breast enlargement in men.

http://www.colorado.edu/MCDB/MCDB2150Fall/notes/L11.html (277 words)



Encyclopedia: X

Semiotics - also known as semiology - is the study of signs, both individually and grouped in sign systems, and includes the study of how meaning is transmitted and understood.
The MPAA film rating system is a system used in the United States and instituted by the Motion Picture Association of America to rate a movie based on its content.
Military science concerns itself with the study and of the diverse technical, psychological, and practical phenomena that encompass the events that make up warfare, especially armed combat.

http://www.nationmaster.com/encyclopedia/X (6962 words)



Maternal-Zygotic Gene Conflict Over Sexb> Determinationb>: Effects of Inbreeding -- Werren and Hatcher 155 (3): 1469 -- Genetics

DETERMINATIONb> of sexb> is one of the earliest and most basic "decisions"
Assortment of maternal-effect and zygotic alleles is shown, where r and s are the sexb> ratios (the proportion of males produced under maternal control or the probability of male determinationb> under zygotic control) coded by A and a alleles, respectively.
sexb> allocation theory has tended to abstract the problem in

http://www.genetics.org/cgi/content/full/155/3/1469 (6962 words)



EVOLUTIONARY BIOLOGY: ON CHROMOSOMES AND SEXb> DETERMINATIONb>

There is an even wider range of sexual systems in teleost fishes, with examples of self-fertilizing hermaphrodites [2], sequential hermaphrodites [3], and environmental sexb> determinationb> [1].
Even within tetrapod vertebrates, however, there is a wide diversity of sexb> determinationb> mechanisms, with many examples of species with genetic sexb> determinationb> but microscopically similar X and Y chromosomes, and numerous cases of environmental sexb> determinationb> [1].
But how does sexb> achieve this effect, and under what circumstances is it worthwhile?

http://scienceweek.com/2004/sc041112-3.htm (1024 words)



Talk:Sexb>-determinationb> system - Wikipedia, the free encyclopedia

From the definition, one could conclude that a sexb>-determinationb> system is a method that, when applied to a certain individual, tells you whether that individual is a male or a female.
In that sense, a sexb>-determinationb> system for dogs would be "look if you can find testicles".
I have read information to the effect that the WW:WZ system for birds AND snakes, (i'm not sure about insects) is a reverse xy system in that as the articles says two of the same chromosomes are needed for male determinationb>, instead of the XX style in human.

http://www.wikipedia.org/wiki/Talk:Sex-determination_system (312 words)



The Caenorhabditis elegans Sexb> Determinationb> Protein FEM-1 Is a CED-3 Substrate That Associates with CED-4 and Mediates Apoptosis in Mammalian Cells -- Chan et al. 275 (24): 17925 -- Journal of Biological Chemistry

elegans sexb> determinationb> pathway, is found to repress
the genetic pathway of sexb> determinationb>, the question arises
Apoptosis is an evolutionarily conserved process that is critical for tissue homeostasis and development including sexb> determinationb>

http://www.jbc.org/cgi/content/full/275/24/17925 (3114 words)



(WO 01/52726) CLASSIFICATION SYSTEM FOR SEXb> DETERMINATIONb> AND TISSUE CHARACTERIZATION

The method of sexb> determinationb> provides additional information about primary sources of systematic tissue variability, namely, the thickness of the dermis and the subcutaneous fat.
(57) Instrumentation and procedures for noninvasively determining the sexb> of human and animal subjects in vivo have been developed based on the irradiation of skin tissue with near infrared light.
Categorization of subjects on the basis of the determinationb> is therefore suitable for further spectral analysis and the measurement of biological and chemical compounds, such as blood analytes.

http://www.wipo.int/ipdl/IPDL-CIMAGES/view/pct/getbykey5?KEY=01/52726.010726 (195 words)



Infectious Sexb>

One of the most interesting environmental changes in sexb> determinationb> involves sexb> changes attendent upon infection with a microorganism.
However, in several wild populations, this system is overridden by cytoplasmic sexb> factors produced by endocytic bacteria.
In the woodlouse Armadillium vugare (a terrestrial isopod), sexb> determinationb> in some populations is determined by a symbiotic bacterium.

http://zygote.swarthmore.edu/sex9.html (198 words)



Rapid Deadenylation and Poly(A)-Dependent Translational Repression Mediated by the Caenorhabditis elegans tra-2 3' Untranslated Region in Xenopus Embryos -- Thompson et al. 20 (6): 2129 -- Molecular and Cellular Biology

tra-2 encodes a membrane protein and may mediate cell communication in the Caenorhabditis elegans sexb> determinationb> pathway.
Puoti, A., Pugnale, P., Belfiore, M., Schlappi, A.-C., Saudan, Z. RNA and sexb> determinationb> in Caenorhabditis elegans: Post-transcriptional regulation of the sexb>-determining tra-2 and fem-3 mRNAs in the Caenorhabditis elegans hermaphrodite.
AREs in embryos (58) and in the mammalian cell-free system (12).

http://mcb.asm.org/cgi/content/full/20/6/2129 (6467 words)



X-chromosome: Definition and Much More From Answers.com

Chromosomal conditions involving the sexb> chromosomes often affect sexb> determinationb> (whether a person has the sexual characteristics of a male or a female), sexual development, and the ability to have children (fertility).
The sexb> chromosome associated with female characteristics, occurring paired in the female and singly in the male sexb>-chromosome pair.
The sexb> chromosome associated with female characteristics in mammals, occurring paired in the female and single in the male.

http://www.answers.com/topic/xy-sex-determination-system (1212 words)



X chromosome - Wikipedia, the free encyclopedia

Chromosomal conditions involving the sexb> chromosomes often affect sexb> determinationb> (whether a person has the sexual characteristics of a male or a female), sexual development, and the ability to have children (fertility).
The sexb> chromosomes are one of the 23 pairs of human chromosomes.
The X chromosome is one of the two sexb> chromosomes in humans and other animals (the other is the Y chromosome).

http://en.wikipedia.org/wiki/X_chromosome (1068 words)



Sexb> Determinationb>

Refined Techniques of FEMcide: foetal sexb>-determinationb> and sexb> pre selection/te...
The Role of Estrogen in Turtle Sexb> Determinationb> and the Effect of PCBs...
Sexb> determinationb> and sexb> linkage in water frogs...

http://www.scienceoxygen.com/biology/360.html (304 words)



Minna Heikkilä. Development of the adreno-genital system. ISBN 951-42-6844-X

After sexb> determinationb> Wnt-4 was downregulated in the testis, but the expression persisted until birth in the ovary.
Although the genetic sexb> of an embryo is determined at conception by the presence or absence of the Y chromosome, both females and males have bipotential, undifferentiated gonads early in their development.
Wnt-4-deficient female mice demonstrated a partial female-to-male sexb> reversal and a reduction in the number of oocytes, while the Müllerian duct was absent from both sexes.

http://herkules.oulu.fi/isbn951426844X (289 words)



Human Anatomy Chapter 27 -- Evolution Atlas

The second function is responsible for the evolution of sexb> and gender.
Sexual individuals that reproduce in a way that produces diverse offspring is much more likely to be genetically represented in future generations than asexual individuals that reproduce genetically identical offspring by mitosis.
Sexb> chromosomes are common in reptiles where either male or female can be the heterozygous sexb>, but sexb> chromosomes are often absent in amphibians and fish.

http://cwx.prenhall.com/bookbind/pubbooks/martini10/chapter27/custom2/deluxe-content.html (289 words)



A novel regulatory mutation in the C. elegans sexb> determinationb> gene tra-2 defines a candidate ligand/receptor interaction site -- Kuwabara 122 (7): 2089 -- Development

Exploring the Envelope: Systematic Alteration in the Sexb>-Determinationb> System of the Nematode Caenorhabditis elegans
Genetic and Molecular Analysis of fox-1, a Numerator Element Involved in Caenorhabditis elegans Primary Sexb> Determinationb>
A novel regulatory mutation in the C. elegans sexb> determinationb> gene tra-2 defines a candidate ligand/receptor interaction site -- Kuwabara 122 (7): 2089 -- Development

http://dev.biologists.org/cgi/content/abstract/122/7/2089 (390 words)



Sox3 Is Required for Gonadal Function, but Not Sexb> Determinationb>, in Males and Females -- Weiss et al. 23 (22): 8084 -- Molecular and Cellular Biology

A second major finding of our study is the absence of sexb> reversal
determinationb> and to provide a model for further studies of
to an analysis of eight patients with 46,XX sexb> reversal, which

http://mcb.asm.org/cgi/content/full/23/22/8084 (5095 words)



VE Glossary

Part of nervous system, which regresses from tip of spinal column up until third lumbar vertebrae at time of birth
Ectodermal thickening in amniotic sac floor; Forerunner of nervous system (spinal cord and brain)
Embryonic tissue layer that develops into muscles, bones and circulatory system

http://www.visembryo.com/baby/gloss.html (4499 words)



Eulimnadia

Step 4: Derive equations describing the biological system
Parameter: "An arbitrary constant whose value describes a characteristic of a system"
A number of evolutionary questions arise in this system:

http://www.zoology.ubc.ca/~otto/Talks/Shrimp/Talk.html (614 words)



Wolbachia in Humans?

infection, hence, when they reproduce, no Wolbachia are reproduced.) Pill bugs have a WZ sexb>-determinationb> system, in contrast to the more common XY system found in humans.
a Darwinian perspective, it makes sense for Wobachia to favor the sexb> that can support the
plants as corn and rye that the mitochondrion is responsible for skewing the sexb> ratio in

http://www.ejnerfulsang.com/Wolbachia.html (614 words)

Topic: Sex-determination <b>system<

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