Phosphorus-insufficient maternal milk is associated with ectopic expression of collagen I and female-specific bony changes in infant mouse cartilages

Abstract Dosage compensation in Drosophila is the mechanism by which X-linked gene expression is made equal in males and females. Proper regulation of this process is critical to the survival of both sexes. Males must turn the male-specific lethal (msl)-mediated pathway of dosage compensation on and females must keep it off. The msl2 gene is the primary target of negative regulation in females. Preventing production of MSL2 protein is sufficient to prevent dosage compensation; however, ectopic expression of MSL2 protein in females is not sufficient to induce an insurmountable level of dosage compensation, suggesting that an additional component is limiting in females. A candidate for this limiting factor is MSL1, because the amount of MSL1 protein in females is reduced compared to males. We have identified two levels of negative regulation of msl1 in females. The predominant regulation is at the level of protein stability, while a second regulatory mechanism functions at the level of protein synthesis. Overcoming these control mechanisms by overexpressing both MSL1 and MSL2 in females results in 100% female-specific lethality.

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Recombination and disjunction in female germ cells of Drosophila depend on the germline activity of the gene sex-lethal

Development ◽

10.1242/dev.126.24.5785 ◽

1999 ◽

Vol 126 (24) ◽

pp. 5785-5794 ◽

Cited By ~ 4

Author(s):

D. Bopp ◽

C. Schutt ◽

J. Puro ◽

H. Huang ◽

R. Nothiger

Keyword(s):

Ectopic Expression ◽

Common Mechanism ◽

Germline Development ◽

Homologous Chromosomes ◽

Male Germline ◽

High Incidence ◽

Germline Expression ◽

Sex Lethal ◽

Female Specific ◽

Dominant Suppressor

Gametogenesis in males and females differs in many ways. An important difference in Drosophila is that recombination between homologous chromosomes occurs only in female meiosis. Here, we report that this process relies on the correct functioning of Sex-lethal (Sxl) which is primarily known as the master gene in somatic sex determination. Certain alleles of this gene (Sxl(fs)) disrupt the germline, but not the somatic function of Sxl and cause an arrest of germ cell development during cystocyte proliferation. Using dominant suppressor mutations that relieve this early block in Sxl(fs) mutant females, we discovered additional requirements of Sxl for normal meiotic differentiation of the oocyte. Females mutant for Sxl(fs) and carrying a suppressor become fertile, but pairing of homologous chromosomes and formation of chiasmata is severely perturbed, resulting in an almost complete lack of recombinants and a high incidence of non-disjunction events. Similar results were obtained when germline expression of wild-type Sxl was compromised by mutations in virilizer (vir), a positive regulator of Sxl. Ectopic expression of a Sxl transgene in premeiotic stages of male germline development, on the other hand, is not sufficient to allow recombination to take place, which suggests that Sxl does not have a discriminatory role in this female-specific process. We propose that Sxl performs at least two tasks in oogenesis: an ‘early’ function in formation of the egg chamber, and a ‘late’ function in progression of the meiotic cell cycle, suggesting that both events are coordinated by a common mechanism.

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Regulation of behavioral and pheromonal aspects of sex determination in Drosophila melanogaster by the Sex-lethal gene.

Genetics ◽

10.1093/genetics/123.3.535 ◽

1989 ◽

Vol 123 (3) ◽

pp. 535-541 ◽

Cited By ~ 1

Author(s):

L Tompkins ◽

S P McRobert

Keyword(s):

Drosophila Melanogaster ◽

Sexual Behavior ◽

Sex Determination ◽

Ectopic Expression ◽

Lethal Gene ◽

Gene Products ◽

Morphological Aspects ◽

Sex Lethal ◽

Normal Males ◽

Female Specific

Abstract We have shown that the Sex-lethal (Sxl) gene, which controls morphological aspects of sex determination in Drosophila melanogaster, also regulates sexual behavior. Chromosomal males that are hemizygous for a deletion of the entire Sxl locus perform normal courtship and synthesize the two courtship-inhibiting pheromones that normal males make. However, ectopic expression of female-specific Sex-lethal gene products drastically alters chromosomal males' ability to perform and elicit courtship and increases the probability that they will synthesize a courtship-stimulating pheromone or fail to synthesize one of the inhibitory pheromones. These observations suggest that male sexual behavior is a consequence of the Sxl gene's being functionally inactive in haplo-X flies.

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Description of Chemosensory Genes in Unexplored Tissues of the Moth Spodoptera littoralis

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.678277 ◽

2021 ◽

Vol 9 ◽

Author(s):

Fotini A. Koutroumpa ◽

Christelle Monsempes ◽

Marie-Christine François ◽

Dany Severac ◽

Nicolas Montagné ◽

...

Keyword(s):

Spodoptera Littoralis ◽

Odorant Receptor ◽

Ectopic Expression ◽

Gustatory Receptor ◽

Ionotropic Receptor ◽

Mating Partner ◽

Large Sets ◽

Chemosensory Genes ◽

Female Specific ◽

Male Specific

Illumina-based transcriptome sequencing of chemosensory organs has become a standard in deciphering the molecular bases of chemical senses in insects, especially in non-model species. A plethora of antennal transcriptomes is now available in the literature, describing large sets of chemosensory receptors and binding proteins in a diversity of species. However, little is still known on other organs such as mouthparts, legs and ovipositors, which are also known to carry chemosensory sensilla. This is the case of the noctuid Spodoptera littoralis, which has been established as a model insect species in molecular chemical ecology thanks to the description of many—but not all—chemosensory genes. To fulfill this gap, we present here an unprecedented transcriptomic survey of chemosensory tissues in this species. RNAseq from male and female proboscis, labial palps, legs and female ovipositors allowed us to annotate 115 putative chemosensory gene transcripts, including 30 novel genes in this species. Especially, we doubled the number of candidate gustatory receptor transcripts described in this species. We also evidenced ectopic expression of many chemosensory genes. Remarkably, one third of the odorant receptors were found to be expressed in the proboscis. With a total of 196 non-overlapping chemosensory genes annotated, the S. littoralis repertoire is one of the most complete in Lepidoptera. We further evaluated the expression of transcripts between males and females, pinpointing sex-specific transcripts. We identified five female-specific transcripts, including one odorant receptor, one gustatory receptor, one ionotropic receptor and one odorant-binding protein, and one male-specific gustatory receptor. Such sex-biased expression suggests that these transcripts participate in sex-specific behaviors, such as host choice for oviposition in females and/or mating partner recognition in both sexes.

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