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Nanocellulose, an exceptional natural material acquired from cellulose, has received tremendous attention over the past decades. This is because of its unique physical characteristics, surface chemistry, functional properties, and biocompatibility. Cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) are two major types of nanocellulose that have received key interest so far. Nanocellulose is commercially produced from wood-based sources. With the ongoing demand for nanocellulose, agricultural wastes and non-woody plants are getting much consideration as cost-efficient alternatives. Water hyacinth (WH) is an alternative source that has shown great prospects for CNC and CNF fabrication. Nanocellulose from WH is proposed for several interesting applications, such as wet-spun filaments, aerogels, packaging films, battery separators, and water filtration, showing promising results. Studies have shown the nanocellulose achieved from WH has a comparable diameter and crystallinity related to the nanocellulose derived from other agricultural wastes, but lower than nanocellulose extracted from wood. Studies were more inclined towards chemical treatments for CNC extraction and mechanical processes for CNF isolation. This review aims to emphasize identifying the true potential of WH as a nanocellulose resource by critical evaluation of the isolation processes, affecting factors on nanocellulose properties, and the foundation of future research for producing sustainable materials. It was perceived that a lot of possibilities remain unexplored as many advanced techniques are yet not well studied for WH nanocellulose extraction. Further, the advantage of being a low-lignin raw material was not properly captured by mapping the more sustainable procedures, which should be a future highlight of WH research. [ABSTRACT FROM AUTHOR]

An increased divergence in characters between species in secondary contact can be shaped by selection against competition for a common resource (ecological character displacement, ECD) or against maladapted hybridization (reproductive character displacement, RCD). These selective pressures can act between incipient species (reinforcement) or well-separated species that already completed the speciation process, but that can still hybridize and produce maladapted hybrids. Here, we investigated two well-separated sexually deceptive orchid species that, unusually, share their specific pollinator. Sympatric individuals of these species are more divergent than allopatric ones in floral characters involved in a mechanical isolating barrier, a pattern suggestive of RCD. To experimentally test this scenario, we built an artificial sympatric population with allopatric individuals. We measured flower characters, genotyped the offspring in natural and artificial sympatry and estimated fertility of hybrids. Different from naturally sympatric individuals, allopatric individuals in artificial sympatry hybridized widely. Hybrids showed lower pollination success and seed viability than parentals. Character displacement did not affect plant pollination success. These findings suggest that RCD evolved between these species to avoid hybridization and that selection on reinforcement may be very strong even in plants with highly specialized pollination. [ABSTRACT FROM AUTHOR]

Systematists and geneticists study biological diversity, but they use different approaches that rarely intersect. A very common pattern that is of interest for both researchers is the rapid evolution of genitalia, a trait of significant taxonomic utility in several sexually reproducing animal clades. The idea that both male and female genitalia are species-specific and play a role in reproductive isolation has long been controversial but has recently gained a renewed interest by speciation and developmental geneticists. Here, I highlight six unresolved questions in genitalia coevolution and I argue that systematists, with their well training in comparative morphology, usage of large and geographically diverse collections, and ability to apply molecular genetics techniques, can make important contributions. Such an extension of systematics into the speciation and developmental genetics realms is a promising opportunity to expand 'integrative taxonomy' comparisons between DNA and morphology into more explanatory relationships between the two sources of taxonomic data. [ABSTRACT FROM AUTHOR]

Stigmaeopsis celarius Banks (hereafter Sc) is a spider mite living and feeding on the leaves of various bamboo species such as Moso bamboo [ Phyllostachys edulis (= P. pubescens)] and Pleioblastus spp. (Poaceae). A previous phylogenetic study revealed a cryptic, phylogenetic sister species to Sc (hereafter Ss). Although its life type appears to be similar to that of Sc, individuals of Ss make much smaller nests compared with Sc, and the nests have been found mostly on Nezasa bamboo ( Pleioblastus argenteostriatus). To investigate whether Sc and Ss are reproductively isolated, we explored their populations in southwestern Japan, and crossed them to examine mating behaviors and fertilization success. Field surveys revealed that the nests of these two species occur on the same leaves and, thus, the individuals of these species may make frequent contact. Reciprocal crosses suggested that the two species are reproductively isolated. Though Sc males have tried to mate with Ss females, copulation seldom occurred because of their long opisthosoma (hind body), which prevented the insertion of the aedeagus into the genitalia of Ss females. In contrast, most Ss males ignored Sc females, and eggs were not fertilized even in the few cases where copulation appeared to occur. These results suggest that strong selection pressure is imposed on body length to prevent interspecific hybridization in the contact area of these species. [ABSTRACT FROM AUTHOR]

Gene flow between hybridizing plant species depends strongly on pollinator behaviour, which affects pollen transfer among floral types and reproductive isolation. We examined bumblebee behaviour and pollen transfer between two hybridizing Rhinanthus species that are very similar in ecology and floral traits. The two species, Rhinanthus minor and R. angustifolius, shared similar pollinator guilds and assemblages, but pollinator recruitment and flower visitation rates were higher in R. angustifolius sites, probably because of its higher reward levels and better visibility. When presented with Rhinanthus flowers, bumblebees that previously foraged on R. angustifolius were less prone to visit R. minor inflorescences, while R. minor foragers accepted both species in similar proportions. Although Rhinanthus has been cited as a case of mechanical isolation resulting from interactions between bee behaviour and differences in stigma and anther placement, we found no support for efficient mechanical reproductive isolation. Bumblebees that foraged on R. minor flowers carried more pollen, but pollen placement on their bodies was similar to that of bees that visited R. angustifolius, and cross-specific stigmatic pollen deposition was similar in both directions. However, the asymmetry in pollinator handling time between the two species, due to dissimilar pollen rewards, may have lowered relative heterospecific pollen receipt on R. angustifolius, suggesting that net gene flow resulting from pollen transfer dynamics is more likely towards R. minor, although this effect remains weak and will be most likely counterbalanced by context-based labile pollinator preference. [ABSTRACT FROM AUTHOR]

This study was designed to investigate an effective method for the derivation of human embryonic stem cells (hESC) from poor quality embryos discarded from in vitro fertilization (IVF) laboratories. Poor quality embryos were donated from IVF center on day 3 and cultured in a blastocyst medium for 2 days, and then in a blastocyst optimum culture medium for additional 2 days. The isolated inner cell masses (ICM) were inoculated onto the feeder layer of mouse embryonic fibroblasts for sub cultivation. The biological characterizations and differentiation capability of these cells were examined after at least 15 passages. Forty-two embryos developed to expanded blastocysts or hatched blastocysts and ICMs were successfully isolated from all embryos. Six new hESC lines were established after further culture. All hESC lines were positive for stage-specific embryonic antigen SSEA-4, TRA-1-81, TRA-1-60 markers and negative for SSEA-1 marker. They showed a high level of alkaline phosphatase activity, positive expression of transcription factor Oct-4. Furthermore, these cells had the potential to form both embryoid bodies in vitro and teratomas in vivo. Five hESC lines had normal karyotypes and one had trisomy 13. In this paper we described a stable and effective system for hESC isolation and established six new hESC lines, which will provide an excellent experimental model for cell therapy, developmental biology and genetic research. [ABSTRACT FROM AUTHOR]