Journal ArticleDOI
Segmental heterogeneity in replication and transcription of the X 2 chromosome of Drosophila miranda and conservativeness in the evolution of dosage compensation
TLDR
Results reveal that there is a considerable amount of heterogeneity among different segments of the X2 but not among the segments of X1 chromosome, and theX2 element appears relatively thinner than X1 in almost all nuclei from male larval glands.Abstract:
A detailed analysis of the replication and transcription patterns of the X chromosomes of Drosophila miranda has been made using 3H-thymidine and 3H-uridine autoradiography. The purpose of this investigation has been to examine the relative duration of replication and hyperactivity of the different regions of the X2 element of this species. Results reveal that there is a considerable amount of heterogeneity among different segments of the X2 but not among the segments of X1 chromosome. Secondly, there is a clear site wise relationship between early replication and hyperactivity in X1 as well as X2. Thirdly, the X2 element appears to replicate relatively earlier than the X1 element in the male. — Our data do not support a spreading effect or polarization in the distribution of hyperactive segments. Furthermore, the X2 element appears relatively thinner than X1 in almost all nuclei from male larval glands. The significance of these results has been discussed in the light of the conservativeness of dosage compensation mechanism in a particular evolutionary line.read more
Citations
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Journal ArticleDOI
Histone acetylation as an epigenetic determinant of long-term transcriptional competence.
TL;DR: The evidence for the role of acetylation in transcriptional control is outlined, using centric heterochromatin and the dosage-compensated male X chromosome in Drosophila as model systems, and suggests possible mechanisms by which it might operate.
Journal ArticleDOI
Reduced adaptation of a non-recombining neo-Y chromosome
TL;DR: In this article, the authors show that a higher rate of protein sequence evolution of the X-linked copy of Cyclin B relative to the neo-Y copy is driven by positive selection, which is consistent with the adaptive hypothesis.
Journal ArticleDOI
Sex chromosome evolution: Molecular aspects of Y-chromosome degeneration in Drosophila
TL;DR: Comparison of four large genomic regions located on the neo-sex chromosomes that contain a total of 12 homologous genes finds that both 5'- and 3'-flanking regions of genes and intron sequences are less constrained on the Nazi-era Y-chromosome compared to its neo-X homolog, which shows surprisingly uniform signs of degeneration.
Journal ArticleDOI
The dosage compensation system of Drosophila is co-opted by newly evolved X chromosomes
TL;DR: It is reported that the sex- and chromosome-specific binding of three of the msl proteins (MSLs) occurs in other drosophilid species, spanning four genera, and it is shown that MSL binding correlates with the evolution of the sex chromosomes.
Journal ArticleDOI
Dosage compensation regulatory proteins and the evolution of sex chromosomes in Drosophila.
James R. Bone,Mitzi I. Kuroda +1 more
TL;DR: Using polytene chromosome immunostaining of other species from the genus Drosophila, it is found that X chromosome association of MSL proteins and H4Ac16 is conserved despite differences in the sex chromosome karyotype between species.
References
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Book
Evolution in the genus Drosophila
J. T. Patterson,Wilson S. Stone +1 more
TL;DR: The most extensive treatment of any living genus thus far attempted, this book deals with the evolution of Drosophila as demonstrated by living forms, and is mainly concerned with isolating mechanisms, genetic systems shown by hybrids and the cytology of over one third of the known species of the genus.
Journal ArticleDOI
Control of X chromosome transcription by the maleless gene in Drosophila
TL;DR: It is reported here that, reasoning that sex- specific lethal mutations may represent lesions in the processes controlling the transcription of X-linked loci, several male-specific lethal mutations are sought and recovered and it is noted that they affect the levels ofX-linked enzyme activities in crude extracts of homozygous male larvae.
Journal ArticleDOI
Gene dosage compensation and the evolution of sex chromosomes.
TL;DR: It is proposed that in both groups of organisms the evolution of heteromorphic sex chromosomes was gradual and occurred as the direct result of the Evolution of dosage compensation rather than the reverse.
Journal ArticleDOI
A male-specific lethal mutation in Drosophila melanogaster that transforms sex.
TL;DR: In addition to its effect on sexual differentiation, Sxl M#1 reduces the size of haplo-X imaginal disc and histoblast derivatives in general in a cell autonomous fashion, suggesting that there is no single localized “lethal focus” for this mutation.