Sexual differentiation in the spiny softshell turtle (Apalone spinifera), a species with genetic sex determination

2001 ◽  
Vol 290 (2) ◽  
pp. 190-200 ◽  
Author(s):  
Eli Greenbaum ◽  
John L. Carr
Keyword(s):  
Sex Determination ◽  
Sexual Differentiation ◽  
Apalone Spinifera ◽  
Softshell Turtle

Sexual differentiation of merozoites of Eimeria tenella

Parasitology ◽  
1972 ◽  
Vol 65 (1) ◽  
pp. 131-136 ◽  
Author(s):  
B. Klimes ◽  
D. G. Rootes ◽  
Zabel Tanielian
Keyword(s):  
Cell Culture ◽  
Sex Determination ◽  
Kidney Cell ◽  
Sexual Differentiation ◽  
Eimeria Tenella ◽  
Kidney Cell Culture ◽  
Pas Staining

In chickens kidney-cell culture gametogony of E. tenella usually occurs in a limited number of selected cells in the form of nests of gametocytes. Some cells contain only macrogametocytes, others only microgametocytes and some cells contain both sexes together. Mixed nests of gametocytes are evidence for genetic sex determination. By using PAS staining the origin of macrogametocytes and microgametocytes can be retraced to the merozoites and schizonts of the last generation, which are differentiated by this technique.

scholarly journals The iso1 gene of Chlamydomonas is involved in sex determination.

1995 ◽  
Vol 6 (1) ◽  
pp. 87-95 ◽  
Author(s):  
A M Campbell ◽  
H J Rayala ◽  
U W Goodenough
Keyword(s):  
Sex Determination ◽  
Chlamydomonas Reinhardtii ◽  
Mating Type ◽  
Dna Sequences ◽  
Sexual Differentiation ◽  
Type Locus ◽  
Mating Structure ◽  
Mating Type Locus

Sexual differentiation in the heterothallic alga Chlamydomonas reinhardtii is controlled by two mating-type loci, mt+ and mt-, which behave as a pair of alleles but contain different DNA sequences. A mutation in the mt minus-linked imp11 gene has been shown previously to convert a minus gamete into a pseudo-plus gamete that expresses all the plus gametic traits except the few encoded by the mt+ locus. Here we describe the iso1 mutation which is unlinked to the mt- locus but is expressed only in minus gametes (sex-limited expression). A population of minus gametes carrying the iso1 mutation behaves as a mixture of minus and pseudo-plus gametes: the gametes isoagglutinate but they do not fuse to form zygotes. Further analysis reveals that individual gametes express either plus or minus traits: a given cell displays one type of agglutinin (flagellar glycoprotein used for sexual adhesion) and one type of mating structure. The iso1 mutation identifies a gene unlinked to the mating-type locus that is involved in sex determination and the repression of plus-specific genes.

scholarly journals A partially sex-reversed giant kelp sheds light into the mechanisms of sexual differentiation in a UV sexual system

2021 ◽  
Author(s):  
Dieter Mueller ◽  
Enora Gachet ◽  
Olivier Godfroy ◽  
Josselin Gueno ◽  
Guillaume Cossard ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sex Determination ◽  
Sexual Differentiation ◽  
Expression Patterns ◽  
Specific Region ◽  
Autosomal Gene ◽  
Giant Kelp ◽  
Developmental Programs ◽  
Male And Female ◽  
Developmental Program

In UV sexual systems, sex is determined during the haploid phase of the life cycle and males have a V chromosome whereas females have a U chromosome. Previous work in the brown algal model Ectocarpus revealed that the V chromosome has a dominant role in male sex determination and suggested that the female developmental program may occur by default, triggered in the absence of the male master sex determination gene(s). Here, we describe the identification of a genetically male giant kelp strain presenting phenotypic features typical of a female, despite lacking the U-specific region. The conversion to the female developmental program is however incomplete, because gametes of this feminised male are unable to produce the sperm-attracting pheromone lamoxirene. We identify the transcriptomic patterns underlying the male and female specific developmental programs, and reveal the faster evolutionary rates of male-biased genes compared to female-biased and unbiased genes. Moreover, we show that the phenotypic feminisation of the variant strain is associated with both feminisation and de-masculinisation of gene expression patterns. Importantly, the feminisation phenotype was associated with the dramatic downregulation of two V-specific genes including a candidate sex-determining gene on the V-specific region. Our results reveal the transcriptional changes associated with sexual differentiation in a UV system with marked sexual dimorphism, and contribute to disentangling the role of sex-linked genes and autosomal gene expression in the initiation of the male and female developmental programs. Overall, the data presented here imply that the U-specific region in the giant kelp is not required to initiate the female developmental program, but is critical to produce fully functional eggs, arguing against the idea that female is the default sex in this species.

A ZZ/ZW microchromosome system in the spiny softshell turtle, Apalone spinifera, reveals an intriguing sex chromosome conservation in Trionychidae

2013 ◽  
Vol 21 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Daleen Badenhorst ◽  
Roscoe Stanyon ◽  
Tag Engstrom ◽  
Nicole Valenzuela
Keyword(s):  
Sex Chromosome ◽  
Apalone Spinifera ◽  
Softshell Turtle

Her, a gene required for sexual differentiation in Drosophila, encodes a zinc finger protein with characteristics of ZFY-like proteins and is expressed independently of the sex determination hierarchy

Development ◽  
1998 ◽  
Vol 125 (2) ◽  
pp. 225-235
Author(s):  
H. Li ◽  
B.S. Baker
Keyword(s):  
Sex Determination ◽  
Sexual Differentiation ◽  
Zinc Finger Protein ◽  
Genetic Characterization ◽  
Zinc Fingers ◽  
Molecular Genetic ◽  
Control Female ◽  
Finger Protein ◽  
Molecular Genetic Characterization

The zygotic function of the hermaphrodite (her) gene of Drosophila plays an important role in sexual differentiation. Our molecular genetic characterization of her suggests that her is expressed sex non-specifically and independently of other known sex determination genes and that it acts together with the last genes in the sex determination hierarchy, doublesex and intersex, to control female sexual differentiation. Consistent with such a terminal function in sexual differentiation, her encodes a protein with C2H2-type zinc fingers. The her zinc fingers are atypical and similar to the even-numbered zinc fingers of ZFY and ZFX proteins in humans and other vertebrates.

MALE SEX DETERMINATION: Current Concepts of Male Sexual Differentiation

1994 ◽  
Vol 45 (1) ◽  
pp. 505-524 ◽  
Author(s):  
Michael L. Gustafson, M.D ◽  
Patricia K. Donahoe, M.D
Keyword(s):  
Sex Determination ◽  
Sexual Differentiation ◽  
Male Sex
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