Phylogeography of Eriotheca species complex: insights into the origin and range expansion of apomictic and polyploid trees in Neotropical Savannas.

Polyploidy and whole genome duplication are major evolutionary drivers in plants. Climate variations during the Pleistocene have influenced distribution and range expansion worldwide. Similar trends have been reported for Cerrado plants, but no attempt has been made to link phylogeography with ploidy and breeding changes. Thus, we aimed to (i) assess ploidy and genome size of Eriotheca estevesiae Carv.-Sobr., and compare it with E. pubescens (Mart.) Schott & Endl. (Both included into the Eriotheca Stellate Trichome Species Complex - ESTSC). (ii) Subsequently, we investigated their phylogeography to see whether genetic structure and range expansion trends were similar to those previously described for the Cerrado biome. Finally (iii), we discuss whether ESTSC phylogeographic patterns could be associated with geographic parthenogenesis processes. Common cytogenetic techniques and flow cytometry were used to confirm chromosome number and genome size of E. estevesiae. We used three cpDNA regions to analyse 14 ESTSC Cerrado populations, for which we also obtained ploidy level and breeding information. We investigated haplotype diversity, population structure and tested neutrality, aiming to reconstruct phylogeographic scenarios. We found three ploidy levels and eight cpDNA haplotypes in ESTSC, one shared by most populations. Haplotype and ploidy distribution corroborated that E. pubescens, the widely distributed polyploid and apomictic species, may have originated from northern diploid and probably sexual E. estevesiae. Matrilinear cpDNA links support the idea that apomixis and polyploidy in ESTSC may have allowed range expansion during the Pleistocene, in a process analogous to the geographic parthenogenesis described elsewhere.

Otodental syndrome: a case report and genetic considerations.

A 5-year-old boy presented with otodental syndrome. His maxillary and mandibular incisors were within normal limits. The premolar/molar areas in all quadrants were occupied by markedly macrodontic teeth showing globular shape. The canines had a similar rounded shape. Two canines and 1 of the other abnormal teeth demonstrated areas of yellow hypoplastic enamel. Radiographs revealed that some of the abnormal teeth had bifurcated pulp chambers and pulp stones. Premolar tooth germs were absent. Audiometry demonstrated that the child had a marked bilateral sensorineural hearing loss for frequencies above 1000 Hz. No other members of the immediate family were clinically affected. The parents of the child were not aware of any similarly affected relatives. Suggestions with respect to possible genetic mechanisms and gene participation in the etiology of this syndrome are offered.