We present the clinical and molecular findings of mosaic ring chromosome 4. The patient was referred to us for infertility and short stature. Results of three repeated cytogenetic analyses from lymphocytes showed a similar mosaic karyotype with multiple cell-lines [46,XX,r(4)/45,XX,–4/46,XX,dic r(4)/47,XX,r(4),+r(4)/46,XX]. FISH showed deletion of the 4p subtelomeric region and the 4q telomeric region from the ring chromosome 4. The breakpoints were mapped using molecular analysis. Parental karyotypes were normal. During the course of this study, the patient became pregnant without assisted reproductive technology. The result of amniocentesis performed at 16 weeks gestation showed a normal karyotype. Delivery was uncomplicated. This is the first report, to our knowledge, of the presence of ring chromosome 4 having various mosaic conditions in a female having a chromosomally normal fetus.

12Comparative genomics of fungal mitochondrial genomes (mitogenomes) have revealed 13 a remarkable pattern of rearrangement between and within major phyla owing to 14 horizontal gene transfer (HGT) and recombination. The role of recombination was 15 exemplified at a finer evolutionary time scale in basidiomycetes group of fungi as they 16 display a diversity of mitochondrial DNA (mtDNA) inheritance patterns. Here, we 17 assembled mitogenomes of six species from the Hymenochaetales order of 18 basidiomycetes and examined 59 mitogenomes from two genetic lineages of 19Pyrrhoderma noxium. Gene order is largely colinear while intergene regions are major 20 determinants of mitogenome size variation. Substantial sequence divergence was found 21 in shared introns consistent with high HGT frequency observed in yeasts, but we also 22 identified a rare case where an intron was retained in five species since speciation. In 23 contrast to the hyperdiversity observed in nuclear genomes of P. noxium, mitogenomes' 24 intraspecific polymorphisms at protein coding sequences are extremely low. Phylogeny 25 based on introns revealed turnover as well as exchange of introns between two lineages. 26Strikingly, some strains harbor a mosaic origin of introns from both lineages. Analysis 27 of intergenic sequence indicated substantial differences between and within lineages, 28 and an expansion may be ongoing as a result of exchange between distal intergenes. 29These findings suggest that the evolution in mtDNAs is usually lineage specific but 30 chimeric mitotypes are frequently observed, thus capturing the possible evolutionary 31 processes shaping mitogenomes in a basidiomycete. The large mitogenome sizes 32 reported in various basidiomycetes appear to be a result of interspecific reshuffling of 33 intergenes. 34 62 mitochondria are typically inherited from the larger gamete (Sandor, et al. 2018). For 63 basidiomycetes, various modes of mitochondrial inheritance may have been involved 64 in generating recombinant mitochondrial genotypes (Xu and He 2015; Xu and Wang 65 2015; Sandor, et al. 2018).66 67 In fungi, tight regulation of mtDNA transmission is part of molecular mechanisms 68 responsible for sex determination (mating). For model basidiomycetes yeast 69 Cryptococcus neoformans, mtDNA is inherited uniparentally from MATa parent 70 butbecomes biparental if the sex-specific homeodomain transcription factor sxi1α and 71 sxi2a are disrupted (Xu, et al. 2000; Yan and Xu 2003). A closely related species of C. 72 neoformans, C. gattii exhibited different inheritance patterns depending on strain 73 combinations and environmental factors such as temperature (Voelz, et al. 2013; Zhu, 74 et al. 2013; Wang, et al. 2015). For U. maydis, which has a tetrapolar mating system 75 similar to the model mushroom Coprinopsis cinerea, the mtDNA inheritance is 76 controlled by lga2 and rga2 of uncertain function encoded by a2 locus (homologous to 77 C. cinerea matB locus) (Fedler, et al. 2009).78 79 Strictly selecting mtDNA from only one parent du...