Publications by authors named "Nathaniel B Edelman"
Introgressed DNA is often deleterious at many loci in the recipient species' genome, and is therefore purged by selection. Here, we use mathematical modeling and whole-genome simulations to study the influence of recombination on this process. We find that aggregate recombination controls the genome-wide rate of purging in the early generations after admixture, when purging is most rapid.
View Article and Find Full Text PDFThe mule deer () is an ungulate species that is distributed in a range from western Canada to central Mexico. Mule deer are an essential source of food for many predators, are relatively abundant, and commonly make broad migration movements. A clearer understanding of the mule deer genome can improve our knowledge of its population genetics, movements, and demographic history, aiding in conservation efforts.
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- Hybrids between certain species, like those of *Heliconius pardalinus*, tend to be sterile, particularly in females, which aligns with Haldane's rule that predicts hybrid unfitness primarily occurs in the heterogametic sex.
- The study focuses on a case of female hybrid sterility resulting from developmental issues in oocytes, revealing that the Z chromosome plays a significant role through complex interactions with other genetic loci.
- This research is groundbreaking as it utilizes genome mapping to understand hybrid sterility in Lepidoptera, confirming the involvement of multiple genes and supporting Haldane's rule's dominance theory.
Article Synopsis
- Introgression, or the transfer of alleles between species, can significantly affect how species evolve and adapt to new environments, particularly in plants.
- Hybrid offspring from different species may not always be viable, but introgression can still add valuable genetic diversity that aids evolution.
- The article highlights that adaptive introgression is especially beneficial for species that are struggling to survive in changing conditions or are expanding their habitats, as it helps them move closer to their fitness optimum.
Article Synopsis
- Heliconius butterflies consist of 48 species and are important for evolutionary studies, but high-quality genome assemblies only exist for two species, Heliconius melpomene and Heliconius erato.
- The authors improved genome assemblies for 16 additional Heliconius species by aligning them to the reference genomes, achieving a high anchoring percentage of their genomes to chromosomes.
- They also identified genomic variations, including repetitive sequences leading to increased gene copies and five major chromosomal inversions that enhance understanding of genetic evolution in these butterflies.
The genomic proportion that two relatives share identically by descent-their genetic relatedness-can vary depending on the history of recombination and segregation in their pedigree. Previous calculations of the variance of genetic relatedness have defined genetic relatedness as the proportion of total genetic map length (cM) shared by relatives, and have neglected crossover interference and sex differences in recombination. Here, we consider genetic relatedness as the proportion of the total physical genome (bp) shared by relatives, and calculate its variance for general pedigree relationships, making no assumptions about the recombination process.
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- * Our research showed that gene flow, or introgression, tends to be less common in areas of the genome that are low in recombination and rich in genes, likely due to the removal of incompatible foreign genes.
- * We discovered a new genetic inversion linked to a color pattern switch that likely transferred between butterfly lineages through introgression, mirroring a similar genetic change in another related lineage.
Identifying the traits causing reproductive isolation and the order in which they evolve is fundamental to understanding speciation. Here, we quantify prezygotic and intrinsic postzygotic isolation among allopatric, parapatric, and sympatric populations of the butterflies Heliconius elevatus and Heliconius pardalinus. Sympatric populations from the Amazon (H.
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- Transposable elements (TEs) significantly influence genome evolution, but their repetitive nature makes them challenging to study and annotate.
- Researchers examined TE content in 19 species of Heliconiine butterflies to understand their role in genomic diversification.
- Findings revealed substantial variations in TE content across species, with some novel SINE lineages appearing and others going extinct, indicating TEs could shape future evolutionary pathways in these butterflies.
The cellular basis of the magnetic sense remains an unsolved scientific mystery. One theory that aims to explain how animals detect the magnetic field is the magnetite hypothesis. It argues that intracellular crystals of the iron oxide magnetite (Fe3O4) are coupled to mechanosensitive channels that elicit neuronal activity in specialized sensory cells.
View Article and Find Full Text PDFHybrid sons between Drosophila melanogaster females and D. simulans males die as 3rd instar larvae. Two genes, D.
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- Hair cells in the inner ear of vertebrates are essential for detecting sound, motion, and gravity through the deflection of their stereocilia.
- A newly discovered iron-rich organelle in the cuticular plate of pigeon hair cells appears to play a role in sensory functions like magnetosensation, and is notable for its unique structure and elemental composition.
- This organelle, found in various bird species but absent in rodents and humans, may serve multiple purposes, such as storing excess iron, stabilizing stereocilia, or aiding in magnetic detection, indicating its importance in avian sensory systems.
The Piwi-interacting RNA (piRNA) pathway defends the germline of animals from the deleterious activity of selfish transposable elements (TEs) through small-RNA mediated silencing. Adaptation to novel invasive TEs is proposed to occur by incorporating their sequences into the piRNA pool that females produce and deposit into their eggs, which then propagates immunity against specific TEs to future generations. In support of this model, the F1 offspring of crosses between strains of the same Drosophila species sometimes suffer from germline derepression of paternally inherited TE families, caused by a failure of the maternal strain to produce the piRNAs necessary for their regulation.
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