scholarly journals Evolution of dosage compensation in Anolis carolinensis , a reptile with XX/XY chromosomal sex determination

2016 ◽  
pp. evw263 ◽  
Author(s):  
Shawn M. Rupp ◽  
Timothy H. Webster ◽  
Kimberly C. Olney ◽  
Elizabeth D. Hutchins ◽  
Kenro Kusumi ◽  
...  
Keyword(s):  
Sex Determination ◽  
Dosage Compensation ◽  
Anolis Carolinensis ◽  
Chromosomal Sex Determination

The dual role of hermaphrodite in the Drosophila sex determination regulatory hierarchy

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 99-111 ◽  
Author(s):  
M.A. Pultz ◽  
B.S. Baker
Keyword(s):  
Sex Determination ◽  
Dosage Compensation ◽  
Regulatory Protein ◽  
Female Offspring ◽  
Normal Female ◽  
Female Development ◽  
Salivary Gland Cells ◽  
Maternal Function ◽  
Different Levels

The hermaphrodite (her) locus has both maternal and zygotic functions required for normal female development in Drosophila. Maternal her function is needed for the viability of female offspring, while zygotic her function is needed for female sexual differentiation. Here we focus on understanding how her fits into the sex determination regulatory hierarchy. Maternal her function is needed early in the hierarchy: genetic interactions of her with the sisterless genes (sis-a and sis-b), with function-specific Sex-lethal (Sxl) alleles and with the constitutive allele SxlM#1 suggest that maternal her function is needed for Sxl initiation. When mothers are defective for her function, their daughters fail to activate a reporter gene for the Sxl early promoter and are deficient in Sxl protein expression. Dosage compensation is misregulated in the moribund daughters: some salivary gland cells show binding of the maleless (mle) dosage compensation regulatory protein to the X chromosome, a binding pattern normally seen only in males. Thus maternal her function is needed early in the hierarchy as a positive regulator of Sxl, and the maternal effects of her on female viability probably reflect Sxl's role in regulating dosage compensation. In contrast to her's maternal function, her's zygotic function in sex determination acts at the end of the hierarchy. This zygotic effect is not rescued by constitutive Sxl expression, nor by constitutive transformer (tra) expression. Moreover, the expression of doublesex (dsx) transcripts appears normal in her mutant females. We conclude that the maternal and zygotic functions of her are needed at two distinctly different levels of the sex determination regulatory hierarchy.

scholarly journals The segmentation gene runt is needed to activate Sex-lethal, a gene that controls sex determination and dosage compensation in Drosophila

1992 ◽  
Vol 59 (3) ◽  
pp. 189-198 ◽  
Author(s):  
Miguel Torres ◽  
Lucas Sanchez
Keyword(s):  
Sex Determination ◽  
Dosage Compensation ◽  
Relative Number ◽  
Initial Step ◽  
The Other ◽  
Loss Of Function ◽  
X Chromosomes ◽  
Segmentation Gene ◽  
Ectopic Activation ◽  
Sex Lethal

SummaryIn Drosophila, sex is determined by the relative number of X chromosomes to autosomal sets (X: A ratio). The amount of products from several X-linked genes, called sisterless elements, is used to indicate to Sex-lethal the relative number of X chromosomes present in the cell. In response to the X: A signal, Sex-lethal is activated in females but remains inactive in males, being responsible for the control of both sex determination and dosage compensation. Here we find that the X-linked segmentation gene runt plays a role in this process. Reduced function of runt results in femalespecific lethality and sexual transformation of XX animals that are heterozygous for Sxl or sis loss-of-function mutations. These interactions are suppressed by SxlMI, a mutation that constitutively expresses female Sex-lethal functions, and occur at the time when the X: A signal determines Sex-lethal activity. Moreover, the presence of a loss-of-function runt mutation masculinizes triploid intersexes. On the other hand, runt duplications cause a reduction in male viability by ectopic activation of Sex-lethal. We conclude that runt is needed for the initial step of Sex-lethal activation, but does not have a major role as an X-counting element.

sdc-1: A link between sex determination and dosage compensation in C. elegans

Cell ◽  
1987 ◽  
Vol 48 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Anne M. Villeneuve ◽  
Barbara J. Meyer
Keyword(s):  
Sex Determination ◽  
Dosage Compensation ◽  
C Elegans

scholarly journals The Caenorhabditis elegans gene sdc-2 controls sex determination and dosage compensation in XX animals.

Genetics ◽  
1989 ◽  
Vol 122 (3) ◽  
pp. 579-593 ◽  
Author(s):  
C Nusbaum ◽  
B J Meyer
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
X Chromosome ◽  
Dosage Compensation ◽  
Apparent Effect ◽  
Linked Gene ◽  
Male Development ◽  
Coordinate Control

Abstract We have identified a new X-linked gene, sdc-2, that controls the hermaphrodite (XX) modes of both sex determination and X chromosome dosage compensation in Caenorhabditis elegans. Mutations in sdc-2 cause phenotypes that appear to result from a shift of both the sex determination and dosage compensation processes in XX animals to the XO modes of expression. Twenty-eight independent sdc-2 mutations have no apparent effect in XO animals, but cause two distinct phenotypes in XX animals: masculinization, reflecting a defect in sex determination, and lethality or dumpiness, reflecting a disruption in dosage compensation. The dosage compensation defect can be demonstrated directly by showing that sdc-2 mutations cause elevated levels of several X-linked transcripts in XX but not XO animals. While the masculinization is blocked by mutations in sex determining genes required for male development (her-1 and fem-3), the lethality, dumpiness and overexpression of X-linked genes are not, indicating that the effect of sdc-2 mutations on sex determination and dosage compensation are ultimately implemented by two independent pathways. We propose a model in which sdc-2 is involved in the coordinate control of both sex determination and dosage compensation in XX animals and acts in the regulatory hierarchy at a step prior to the divergence of the two pathways.

Genetic evidence that the sans fille locus is involved in Drosophila sex determination.

Genetics ◽  
1988 ◽  
Vol 120 (1) ◽  
pp. 159-171
Author(s):  
B Oliver ◽  
N Perrimon ◽  
A P Mahowald
Keyword(s):  
Sex Determination ◽  
Dosage Compensation ◽  
Germ Line ◽  
Ovarian Tumors ◽  
Lethal Gene ◽  
Nurse Cells ◽  
Loss Of Function ◽  
Wild Type ◽  
Sex Lethal

Abstract Females homozygous for sans fille1621 (= fs(1)1621) have an abnormal germ line. Instead of producing eggs, the germ-line cells proliferate forming ovarian tumors or excessive numbers of nurse cells. The Sex-lethal gene product(s) regulate the branch point of the dosage compensation and sex determination pathways in the soma. The role of Sex-lethal in the germ line is not clear but the germ line of females homozygous for female sterile Sex-lethal alleles or germ-line clones of loss-of-function alleles are characterized by ovarian tumors. Females heterozygous for sans fille1621 or Sex-lethal are phenotypically wild type with respect to viability and fertility but females trans-heterozygous for sans fille1621 and Sex-lethal show ovarian tumors, somatic sexual transformations, and greatly reduced viability.

scholarly journals Cytogenetics of the Brazilian whiptail lizard Cnemidophorus littoralis (Teiidae) from a restinga area (Barra de Maricá) in Southeastern Brazil

2004 ◽  
Vol 64 (3b) ◽  
pp. 661-667 ◽  
Author(s):  
D. Peccinini-Seale ◽  
C. F. D. Rocha ◽  
T. M. B. Almeida ◽  
A. F. B. Araújo ◽  
M. A. De Sena
Keyword(s):  
New Species ◽  
Sex Determination ◽  
Diploid Number ◽  
Nucleolar Organizer ◽  
Southeastern Brazil ◽  
Nucleolar Organizer Regions ◽  
Interphase Nuclei ◽  
Determination Mechanism ◽  
A New Species ◽  
Chromosomal Sex Determination

Chromosomes of Cnemidophorus littoralis, a new species of teiid lizard recently described, were studied. The animals are from a restinga area in Barra de Maricá, RJ. The karyotype presents a diploid number of 2n = 46 chromosomes and a chromosomal sex determination mechanism of the type XX:XY. Nucleolar organizer regions, Ag-NORs, are at the sixth pair of chromosomes; there is variability of size and number of the Ag-stained nucleoli on the 50 interphase nuclei for each specimen analyzed. These nucleoli are related to NOR patterns that also demonstrated variability in size and number. This paper presents the first description of the karyotype of Cnemidophorus littoralis and of a chromosomal sex determination mechanism of the XX:XY type in the genus Cnemidophorus from Southeastern Brazil.

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