RESUMO
Prehistoric Japan underwent rapid transformations in the past 3000 years, first from foraging to wet rice farming and then to state formation. A long-standing hypothesis posits that mainland Japanese populations derive dual ancestry from indigenous Jomon hunter-gatherer-fishers and succeeding Yayoi farmers. However, the genomic impact of agricultural migration and subsequent sociocultural changes remains unclear. We report 12 ancient Japanese genomes from pre- and postfarming periods. Our analysis finds that the Jomon maintained a small effective population size of ~1000 over several millennia, with a deep divergence from continental populations dated to 20,000 to 15,000 years ago, a period that saw the insularization of Japan through rising sea levels. Rice cultivation was introduced by people with Northeast Asian ancestry. Unexpectedly, we identify a later influx of East Asian ancestry during the imperial Kofun period. These three ancestral components continue to characterize present-day populations, supporting a tripartite model of Japanese genomic origins.
RESUMO
The taxonomy of Pseudolachnea and Pseudolachnella is controversial. Some authors have regarded them as congeneric, whereas others have considered them to be distinct genera differentiated merely on the number of conidial septa. A total of 26 isolates of Pseudolachnea-like fungi were subjected to morphological examination and phylogenetic analyses of nuc rDNA internal transcribed spacers 1 and 2 and partial 28S sequences and partial sequence of the translation elongation factor 1α gene. The results indicated that our materials should be classified in four genera: Pseudolachnea, Pseudolachnella, and two new genera, Neopseudolachnella and Pseudodinemasporium. Although the monophyly of both Pseudolachnea and Pseudolachnella was confirmed, it was concluded that differences observed in the conidiomatal structure, such as thickness of basal stroma and the excipulum, were more reliable for their circumscription, instead of conidial septation. Neopseudolachnella was similar to Pseudolachnea and Pseudolachnella in conidial morphology but was characterized by the conidiomata lacking an excipulum, unlike members of the latter two genera. Pseudodinemasporium bore conidia morphologically similar to those of Dinemasporium but was differentiated from the latter by the conidiomata, which was composed of a well developed peridial structure. A total of 12 new species, namely three in Neopseudolachnella (N. acutispora, N. magnispora, N. uniseptata), one in Pseudodinemasporium (P. fabiforme) and eight in Pseudolachnella (P. asymmetrica, P. botulispora, P. brevicoronata, P. campylospora, P. complanata, P. falcatispora, P. fusiformis and P. pachyderma) are described and illustrated.
