Approximate Bayesian computation supports a high incidence of chromosomal mosaicism in blastocyst-stage human embryos.

Chromosome mis-segregation is common in human meiosis and mitosis, and the resulting aneuploidies are the leading cause of pregnancy loss. Preimplantation genetic testing for aneuploidy (PGT-A) seeks to prioritize chromosomally normal embryos for transfer based on genetic analysis of a biopsy of approximately five trophectoderm cells from blastocyst-stage fertilized (IVF) embryos. While modern PGT-A platforms classify these biopsies as aneuploid, euploid, or mosaic (possessing a mixture of normal and aneuploid cells), the underlying incidences of aneuploid, euploid, and mosaic embryos and the rates of meiotic and mitotic error that produced them remain largely unknown.

A method for low-coverage single-gamete sequence analysis demonstrates adherence to Mendel's first law across a large sample of human sperm.

Recently published single-cell sequencing data from individual human sperm (=41,189; 969-3377 cells from each of 25 donors) offer an opportunity to investigate questions of inheritance with improved statistical power, but require new methods tailored to these extremely low-coverage data (∼0.01× per cell). To this end, we developed a method, named rhapsodi, that leverages sparse gamete genotype data to phase the diploid genomes of the donor individuals, impute missing gamete genotypes, and discover meiotic recombination breakpoints, benchmarking its performance across a wide range of study designs.

Biased introgression of mitochondrial and nuclear genes: a comparison of diploid and haplodiploid systems.

Hybridization between recently diverged species, even if infrequent, can lead to the introgression of genes from one species into another. The rates of mitochondrial and nuclear introgression often differ, with some taxa showing biases for mitochondrial introgression and others for nuclear introgression. Several hypotheses exist to explain such biases, including adaptive introgression, sex differences in dispersal rates, sex-specific prezygotic isolation and sex-specific fitness of hybrids (e.