Chromosomal diversity in two synchronopatric species of Hoffmannseggella (Orchidaceae)

Hoffmannseggella viridiflora Verola & Semir (Laeliinae, Orchidaceae) is a recently discovered species in the campos rupestres vegetation of the Espinhaço Range, MG, Brazil, in synchronopatry with H. bradei (Pabst) V. P. Castro & Chiron. Both morphological and phenological studies indicate that these species are closely related. To substantiate the differentiation of these two species we examined their chromosome numbers and morphologies. The two species had different chromosome numbers, with H. bradei having 2n = 40 and H. viridiflora having 2n = 44 chromosomes, an aneuploid number not previously documented in the genus. Meiotic behavioral studies undertaken with H. bradei revealed many abnormalities related to bivalent numbers and chromosome migration, suggesting that meiotic abnormalities could generate aneuploid gametes and perhaps aneuploid zygotes. Karyotype formulas and chromosome morphologies are quite different between the species, so H. viridiflora was not directly derived from H. bradei through simple chromosome additions. Complementary analyses are necessary to understand the process and species involved in the origin of H. viridiflora.     

Growth characteristics of Adiantum reniforme var. sinensis and A. capillus‐veneris in response to light and soil moisture

Adiantum reniforme var. sinensis (Adiantaceae) is an endangered fern endemic to the Three Gorges region in southwest China. To elucidate possible ecophysiological mechanisms restricting its distribution, effects of the availability of light (28%, 14% and 7% of open field) and soil moisture (60% and 40% of field capacity) on dry matter production and allocation, leaf morphology and water use efficiency (WUE) were examined in A. reniforme var. sinensis and its widespread congener A. capillus‐veneris. Both species had lower root/shoot ratio (R/S) and higher specific leaf area (SLA) when grown at low light. However, A. reniforme var. sinensis showed less plasticity for total leaf area (LA) and leaf area ratio (LAR) than A. capillus‐veneris, and its root mass, total mass and WUE decreased as light availability decreased. Under water stress, all traits of both species except WUE were significantly affected. However, drought stress decreased total mass of A. capillus‐veneris but did not have a significant effect on A. reniforme var. sinensis. Compared with A. capillus‐veneris, A. reniforme var. sinensis had significantly higher R/S but lower values for other analyzed traits. These results suggest that A. reniforme var. sinensis is relatively superior in drought tolerance but inferior at low light, allowing it to persist in habitats with low soil moisture and high light availability but with few coexisting species present.     

Pradosia restingae sp. nov. from the Atlantic forest,Brazil

Pradosia restingae Terra‐Araujo, a new species of Sapotaceae (Chrysophylloideae) from the Brazilian Atlantic forest is described and illustrated. It is only known from the southern coast of the State Rio Grande do Norte and is likely restricted to the coastal sand dune ecosystem, locally known as the restinga forest, from which the epithet is derived. The species is naturally common, but due the low number of known subpopulations we assign P. restingae a preliminary conservation status of ‘Endangered’ (EN).     

Two new polypores (Ceriporiopsis lavendula and Skeletocutis inflata spp. nov.) from Guangdong Province,China

Two new polypores (Ceriporiopsis lavendula B. K. Cui sp. nov. and Skeletocutis inflata B. K. Cui sp. nov.) are described from the Guangdong Province in southern China. Ceriporiopsis lavendula is characterized by having resupinate basidiocarps with lavender to grayish blue pore surface and very thin to almost absent subiculum, a monomitic hyphal system with clamped generative hyphae, and oblong‐ellipsoid to ellipsoid basidiospores. Moreover, it grows on wood of Castanopsis exclusively. Skeletocutis inflata is characterized by having pileate basidiocarps, smaller pores (8–10 per mm), inflated and partly dissolved skeletal hyphae in KOH. In addition, its tramal skeletal hyphae are parallel along the tubes. Identification keys to species of Ceriporiopsis and Skeletocutis occurring in China are provided.     

Two new Andean species of Neocorynura (Hymenoptera: Halictidae: Augochlorini) with notes on their biology

We describe and illustrate the male, female, and pupa of two new species of Neocorynura from the Colombian Andes, and provide information on their nesting behavior, host plants and social organization. Nests of Neocorynura iguaquensis sp. nov. Smith‐Pardo & Gonzalez and N. muiscae sp. nov. Smith‐Pardo & Gonzalez were found in flat or vertical banks, and contained one to three adult females. The percentage of multi‐female nests varied considerably from 8.3% to 40% of the total of dissected nests at different times in 2000 and 2003. The ovarian development, wing and mandibular wear of females in the nests with two or more females indicated that they were the offspring that remained in the nest before dispersal or a mother and a newly emerged daughter. Pollen taken from the nest cells and scopae of museum specimens showed that both species rely heavily on pollen of asteraceans and may be active year‐round. Details on the nest architecture and comments on the phylogenetic placement of both species are also provided. Direct observations on the multi‐female nests are required to determine whether or not such nests contain temporary assemblages or truly semisocial colonies.

Resumen

Describimos e ilustramos el macho, hembra y pupa de dos especies nuevas de Neocorynura de los Andes colombianos, y proporcionamos información sobre su biología de nidificación, plantas hospederas y organización social. Los nidos de Neocorynura iguaquensis sp. nov. Smith‐Pardo & Gonzalez y N. muiscae sp. nov. Smith‐Pardo & Gonzalez fueron encontrados en el suelo, en áreas planas o barrancos verticales, y tenían de una a tres hembras adultas. El porcentaje de nidos con más de una hembra varió considerablemente desde 8.3% al 40% del total de nidos disectados a diferentes meses en el año 2000 y 2003. El desarrollo ovárico, desgaste de las alas y mandíbulas de las hembras en los nidos con dos o más hembras indicaron que ellas fueron las crías que permanecieron en el nido antes de dispersarse o una madre con la hija recién nacida. El polen tomado de las celdas de cría y escopas de especimenes de museo mostró que ambas especies dependen principalmente de asteraceas y que podrían estar activas todo el año. También oferecemos detalles de la arquitectura del nidos y comentarios sobre la posición filogenética de ambas especies. Observaciones directas de los nido con más de una hembra son necesarias para determinar si tales nidos son agrupaciones temporales o verdaderas colonias semisociales.     

Migrations of Leptophlebia vespertina L. and L. marginata L. (Ins.: Ephemeroptera) in the estuary of a coastal stream

Investigations carried out in a coastal stream flowing to the Northern Bothnian Sea (Ängerån, 63°35'N, 19°50'E) have shown a high drift rate of mayfly nymphs towards the coastal areas. The nymphal development takes place in the estuaries with low salinity (conductivity between 47 and 9800 μS; salinity between 0 and 4–5%₀). After the emergence (May/June) the adults fly from the coastal areas to lay their eggs in the stream biotope in the Ängerån. There thus appears to be a colonization cycle between the coastal stream and adjacent coastal areas. The migration movements of downstream drift and the compensatory upstream directed flight are interpreted as asurvival strategy of the species concerned.     

miR‐10a restores human mesenchymal stem cell differentiation by repressing KLF4

miRNAs have recently been shown to play a significant role in human aging. However, data demonstrating the effects of aging‐related miRNAs in human mesenchymal stem cells (hMSCs) are limited. We observed that hMSC differentiation decreased with aging. We also identified that miR‐10a expression was significantly decreased with age by comparing the miRNA expression of hMSCs derived from young and aged individuals. Therefore, we hypothesized that the downregulation of miR‐10a may be associated with the decreased differentiation capability of hMSCs from aged individuals. Lentiviral constructs were used to up‐ or downregulate miR‐10a in young and old hMSCs. Upregulation of miR‐10a resulted in increased differentiation to adipogenic, osteogenic, and chondrogenic lineages and in reduced cell senescence. Conversely, downregulation of miR‐10a resulted in decreased cell differentiation and increased cell senescence. A chimeric luciferase reporter system was generated, tagged with the full‐length 3′‐UTR region of KLF4 harboring the seed‐matched sequence with or without four nucleotide mutations. These constructs were cotransfected with the miR‐10a mimic into cells. The luciferase activity was significantly repressed by the miR‐10a mimic, proving the direct binding of miR‐10a to the 3′‐UTR of KLF4. Direct suppression of KLF4 in aged hMSCs increased cell differentiation and decreased cell senescence. In conclusion, miR‐10a restores the differentiation capability of aged hMSCs through repression of KLF4. Aging‐related miRNAs may have broad applications in the restoration of cell dysfunction caused by aging. J. Cell. Physiol. 228: 2324–2336, 2013. © The Authors. Published by Wiley Periodicals, Inc.