scholarly journals Purifying Selection Maintains Dosage-Sensitive Genes during Degeneration of the Threespine Stickleback Y Chromosome

2015 ◽  
Vol 32 (8) ◽  
pp. 1981-1995 ◽  
Author(s):  
Michael A. White ◽  
Jun Kitano ◽  
Catherine L. Peichel
Keyword(s):  
Y Chromosome ◽  
Purifying Selection ◽  
Threespine Stickleback

scholarly journals Assembly of the threespine stickleback Y chromosome reveals convergent signatures of sex chromosome evolution

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Catherine L. Peichel ◽  
Shaugnessy R. McCann ◽  
Joseph A. Ross ◽  
Alice F. S. Naftaly ◽  
James R. Urton ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Threespine Stickleback ◽  
Sex Chromosome Evolution

scholarly journals Inefficient purifying selection: the mammalian Y chromosome in the rodent genus Mus

2006 ◽  
Vol 17 (1) ◽  
pp. 14-21
Author(s):  
Sara A. Sandstedt ◽  
Priscilla K. Tucker
Keyword(s):  
Y Chromosome ◽  
Purifying Selection

scholarly journals Positive and Purifying Selection on the Drosophila Y Chromosome

2014 ◽  
Vol 31 (10) ◽  
pp. 2612-2623 ◽  
Author(s):  
Nadia D. Singh ◽  
Leonardo B. Koerich ◽  
Antonio Bernardo Carvalho ◽  
Andrew G. Clark
Keyword(s):  
Y Chromosome ◽  
Purifying Selection

scholarly journals Plant Y Chromosome Degeneration Is Retarded by Haploid Purifying Selection

2011 ◽  
Vol 21 (17) ◽  
pp. 1475-1479 ◽  
Author(s):  
Margarita V. Chibalina ◽  
Dmitry A. Filatov
Keyword(s):  
Y Chromosome ◽  
Purifying Selection ◽  
Y Chromosome Degeneration

scholarly journals Assembly of a young vertebrate Y chromosome reveals convergent signatures of sex chromosome evolution

2019 ◽  
Author(s):  
Catherine L. Peichel ◽  
Shaugnessy R. McCann ◽  
Joseph A. Ross ◽  
Alice F. S. Naftaly ◽  
James R. Urton ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Gasterosteus Aculeatus ◽  
Sex Chromosome ◽  
Bac Library ◽  
Artificial Chromosome ◽  
Threespine Stickleback ◽  
Evolutionary Forces ◽  
Y Chromosomes ◽  
Long Read

AbstractHeteromorphic sex chromosomes have evolved repeatedly across diverse species. Suppression of recombination between X and Y chromosomes leads to rapid degeneration of the Y chromosome. However, these early stages of degeneration are not well understood, as complete Y chromosome sequence assemblies have only been generated across a handful of taxa with ancient sex chromosomes. Here we describe the assembly of the threespine stickleback (Gasterosteus aculeatus) Y chromosome, which is less than 26 million years old. Our previous work identified that the non-recombining region between the X and the Y spans ∼17.5 Mb on the X chromosome. Here, we combined long-read PacBio sequencing with a Hi-C-based proximity guided assembly to generate a 15.87 Mb assembly of the Y chromosome. Our assembly is concordant with cytogenetic maps and Sanger sequences of over 90 Y chromosome clones from a bacterial artificial chromosome (BAC) library. We found three evolutionary strata on the Y chromosome, consistent with the three inversions identified by our previous cytogenetic analyses. The young threespine stickleback Y shows convergence with older sex chromosomes in the retention of haploinsufficient genes and the accumulation of genes with testis-biased expression, many of which are recent duplicates. However, we found no evidence for large amplicons found in other sex chromosome systems. We also report an excellent candidate for the master sex-determination gene: a translocated copy of Amh (Amhy). Together, our work shows that the same evolutionary forces shaping older sex chromosomes can cause remarkably rapid changes in the overall genetic architecture on young Y chromosomes.

scholarly journals Why Chromosome Palindromes?

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Esther Betrán ◽  
Jeffery P. Demuth ◽  
Anna Williford
Keyword(s):  
Gene Conversion ◽  
Y Chromosome ◽  
Adaptive Evolution ◽  
Purifying Selection ◽  
Duplicate Gene ◽  
Adaptive Significance ◽  
Deleterious Mutations ◽  
Initial Fixation ◽  
Selection For ◽  
Y Degeneration

We look at sex-limited chromosome (Y or W) evolution with particular emphasis on the importance of palindromes. Y chromosome palindromes consist of inverted duplicates that allow for local recombination in an otherwise nonrecombining chromosome. Since palindromes enable intrachromosomal gene conversion that can help eliminate deleterious mutations, they are often highlighted as mechanisms to protect against Y degeneration. However, the adaptive significance of recombination resides in its ability to decouple the evolutionary fates of linked mutations, leading to both a decrease in degeneration rate and an increase in adaptation rate. Our paper emphasizes the latter, that palindromes may exist to accelerate adaptation by increasing the potential targets and fixation rates of incoming beneficial mutations. This hypothesis helps reconcile two enigmatic features of the “palindromes as protectors” view: (1) genes that are not located in palindromes have been retained under purifying selection for tens of millions of years, and (2) under models that only consider deleterious mutations, gene conversion benefits duplicate gene maintenance but not initial fixation. We conclude by looking at ways to test the hypothesis that palindromes enhance the rate of adaptive evolution of Y-linked genes and whether this effect can be extended to palindromes on other chromosomes.

scholarly journals High rate of translocation-based gene birth on the Drosophila Y chromosome

2017 ◽  
Vol 114 (44) ◽  
pp. 11721-11726 ◽  
Author(s):  
Ray Tobler ◽  
Viola Nolte ◽  
Christian Schlötterer
Keyword(s):  
Y Chromosome ◽  
Molecular Mechanisms ◽  
Evolutionary Dynamics ◽  
Purifying Selection ◽  
High Rate ◽  
Linked Gene ◽  
The Past ◽  
New Genes ◽  
Gene Acquisition ◽  
Next Generation Sequencing Ngs

The Y chromosome is a unique genetic environment defined by a lack of recombination and male-limited inheritance. The Drosophila Y chromosome has been gradually acquiring genes from the rest of the genome, with only seven Y-linked genes being gained over the past 63 million years (0.12 gene gains per million years). Using a next-generation sequencing (NGS)-powered genomic scan, we show that gene transfers to the Y chromosome are much more common than previously suspected: at least 25 have arisen across three Drosophila species over the past 5.4 million years (1.67 per million years for each lineage). The gene transfer rate is significantly lower in Drosophila melanogaster than in the Drosophila simulans clade, primarily due to Y-linked retrotranspositions being significantly more common in the latter. Despite all Y-linked gene transfers being evolutionarily recent (<1 million years old), only three showed evidence for purifying selection (ω ≤ 0.14). Thus, although the resulting Y-linked functional gene acquisition rate (0.25 new genes per million years) is double the longer-term estimate, the fate of most new Y-linked genes is defined by rapid degeneration and pseudogenization. Our results show that Y-linked gene traffic, and the molecular mechanisms governing these transfers, can diverge rapidly between species, revealing the Drosophila Y chromosome to be more dynamic than previously appreciated. Our analytical method provides a powerful means to identify Y-linked gene transfers and will help illuminate the evolutionary dynamics of the Y chromosome in Drosophila and other species.

Sign in / Sign up

Export Citation Format

Share Document