Mary L. Berbee

Fungal Molecular Evolution: Gene Trees and Geologic Time

Fungal phylogenetics has always been based on characters, but technological and intellectual advances are introducing new kinds of characters and new ways of thinking about them. First light microscopy, then electron microscopy, and now DNA sequencing successively upset previous views of fungal relationships. Phenetics, cladistics, and computerized data analysis and phylogenetic tree generation are now changing the intellectual rules for taxonomy and phylogenetics. The combination of new characters and new analytical tools have supported some taxonomic groups, established some new ones, and demolished a few old ones.

Is Penicillium monophyletic? An evaluation of phylogeny in the family Trichocomaceae from 18S, 5.8S and ITS ribosomal DNA sequence data.

AbstractUsing ribosomal DNA sequences from 17 fungi, we evaluated the monophylly of Penicillium and the phylogeny in the ascomycete family Trichocomaceae (= Eurotiaceae). We determined the 5.8S and...

Aliquandostipitaceae, a new family for two new tropical ascomycetes with unusually wide hyphae and dimorphic ascomata

In two short surveys of lignicolous, fruitbody-forming ascomycetes in Thailand and southern China, six species were found, of which five were new to science. Two fungi with affinity to the Dothideomycetes, one from Thailand and one from China, are described here in the new genus ALIQUANDOSTIPITE: and included in the new family Aliquandostipitaceae. Aliquandostipite khaoyaiensis was found in a tropical rain forest in Thailand and A. sunyatsenii in a small stream in southern China. Both new species are closely related based on morphological and molecular characteristics and with uncertain affinity to other taxa of the Euascomycetes based on phylogenetic analyses of SSU rDNA sequences. The distinguishing features of the new species are the presence of both sessile and stalked ascomata side by side on the substratum and the widest hyphae known from ascomycetes.

ULTRASTRUCTURAL AND LIGHT MICROSCOPIC LOCALIZATION OF CARBOHYDRATES AND PEROXIDASE/CATALASES IN LAGENIDIUM GIGANTEUM ZOOSPORES

Zoospores ofthe oomycete Lagenidium giganteum specifically recognize and then encyst upon mosquito larvae. As a step towards understanding the basis for this specific recognition, we examined the ultrastructure and cytochemistry of the zoospores. Zoospore shape and organellar arrangement are similar in E giganteum and other secondary-type oomycete zoospores. The ultrastructure of zoospores of L. giganteum differs from other Oomycetes mainly in details of vesicle morphology and mitochondrial arrangement. In our studies, we emphasized the outer surface of the zoospores where recognition molecules are likely to be present. Using silver methenamine and thiosemicarbazide-silver proteinate stain sequences, carbohydrate was found at the plasma membrane of zoospores. Ferritin- and fluorescein-labelled concanavalin A binding patterns indicated a-D-mannosyl and/or a-D-glucosyl residues are exposed on the outer surface of the plasma membrane of the zoospore and the wall of the cyst. Within the zoospores, the membranes of small peripheral vesicles, and the membranes and contents of golgi apparati and peripheral cisternae showed evidence of carbohydrate content with silver staining. We did not find clear evidence of carbohydrates among the contents of the large and small peripheral vesicles. Zoospores treated with diaminobenzidine to visualize peroxidases and catalases exhibited increased light and electron opacity in their mitochondria, as well as a fuzzy coat on the external surfaces