The effect of global warming on the Australian endemic orchid Cryptostylis leptochila and its pollinator.

Ecological stability together with the suitability of abiotic conditions are crucial for long-term survival of any organism and the maintenance of biodiversity and self-sustainable ecosystems relies on species interactions. By influencing resource availability plants affect the composition of plant communities and ultimately ecosystem functioning. Plant-animal interactions are very complex and include a variety of exploitative and mutualistic relationships. One of the most important mutualistic interactions is that between plants and their pollinators. Coevolution generates clustered links between plants and their pollen vectors, but the pollination and reproductive success of plants is reduced by increase in the specialization of plant-animal interactions. One of the most specialized types of pollination is sexual deception, which occurs almost exclusively in Orchidaceae. In this form of mimicry, male insects are attracted to orchid flowers by chemical compounds that resemble insect female sex pheromones and pollinate the flowers during attempted copulations. These interactions are often species-specific with each species of orchid attracting only males of one or very few closely related species of insects. For sexually deceptive orchids the presence of a particular pollen vector is crucial for reproductive success and any reduction in pollinator availability constitutes a threat to the orchid. Because global warming is rapidly becoming the greatest threat to all organisms by re-shaping the geographical ranges of plants, animals and fungi, this paper focuses on predicting the effect of global warming on Cryptostylis leptochila, a terrestrial endemic in eastern Australia that is pollinated exclusively via pseudo copulation with Lissopimpla excelsa. As a species with a single pollinator this orchid is a perfect model for studies on the effect of global warming on plants and their pollen vectors. According to our predictions, global warming will cause a significant loss of suitable niches for C. leptochila. The potential range of this orchid will be 36%-75% smaller than currently and as a result the Eastern Highlands will become unsuitable for C. leptochila. On the other hand, some new niches will become available for this species in Tasmania. Simultaneously, climate change will result in a substantial expansion of niches suitable for the pollinator (44-82%). Currently ca. 71% of the geographical range of the orchid is also suitable for L. excelsa, therefore, almost 30% of the areas occupied by C. leptochila already lack the pollen vector. The predicted availability of the pollen vector increased under three of the climate change scenarios analysed. The predicted habitat loss is a serious threat to this orchid even with the potential colonization of Tasmania by this plant. In the reduced range of C. leptochila the pollen vector will also be present assuring fruit set in populations of this orchid. The genetic pool of the populations in New South Wales and Queensland will probably be lost.

Short-term cell death in tissues of Pulsatilla vernalis seeds from natural and ex situ conserved populations.

Pulsatilla vernalis is a IUCN listed species that occurs in mountain and lowland habitats. The seeds collected from different populations are remarkably diverse in their viability depending on locality or year of collection. We aim to analyse seed viability, among others, by investigation of the percentage of alive, dying, and dead cells in embryos and endosperm when comparing the seeds from a wild lowland population and ex situ cultivation of plants of lowland and Alpine origin. The cell death was detected by staining with two fluorescence probes, one penetrating only the changed nuclear membranes, the other penetrating also the unchanged cells. 54.5% of Alpine origin seeds were presumably capable of germination if they were sown after collection, however, four months later only 36.4% had healthy embryos. In the case of lowland wild plants it was 31.8% and 18.2%, and from ex situ, 27.3% and 13.6%, respectively. 27.3% of Alpine origin seeds had embryo in torpedo stage (9.1% in the case of lowland seeds). Mean weight of the former was 2.9 mg (2.0 mg in lowland ones). Our results confirm the significance of seed origin and seed weight on viability, and that Pulsatilla seeds have a short 'germination time window'.

The impact of global warming on the niches and pollinator availability of sexually deceptive orchid with a single pollen vector.

Orchidaceae are among the most endangered plants in the world. Considering the sensitive nature of pollinator-plant relationship the most vulnerable are species which are dependent on a single pollen vector. In this paper the future distribution of suitable niches of Australian sexually deceptive orchid Leporella fimbriata and its pollinator (Myrmecia urens) was estimated using three machine learning algorithms. While the potential range of fringed hare orchid depending on modelling method will be larger or slightly reduced than currently observed, the ant will face significant loss of suitable niches. As a result of global warming the overlap of orchid and its only pollen vector will most probably decrease. The unavailability of pollen vector will lead to decreased reproductive success and as a result it will be a great threat for L. fimbriata existence.

Allelic isoforms of the chicken and duck histone H1.a.

Two isoforms of the erythrocyte histone H1.a were identified in two conservative flocks of Rhode Island Red chickens and six conservative flocks of ducks. The H1.a1 and H1.a2 isoforms formed three phenotypes (a1, a2 and a1a2) and were electrophoretically similar in the two species. The frequency of phenotype and histone H1.a allele occurrence varied within the genetic groups of birds, but the relatively rare allele a(2) was only detected in chicken and duck strains with colored feathers. Using mass spectrometry, we established that the difference between the measured masses of the duck H1.a isoforms was 156 Da. Since this value corresponds to the mass of the arginine residue alone or to the combined mass of the valine and glycine residues, we believe that the polymorphism of duck histone H1.a might have originated from sequence variation. A mass difference of 1 Da observed between chicken H1.a isoforms corresponded well to the previously detected Glu/Lys substitution (0.9414 Da) at position 117.

Linker histone H1.b is polymorphic in grey partridge (Perdix perdix).

This study was aimed at characterizing allelic variations of erythrocyte histone H1.b by comparing the electrophoretic patterns of histone H1.b from individuals of grey partridge (Perdix perdix) population. As two alloforms, H1.b1 and H1.b2, were discerned in the screening gels, the histone H1.b was regarded to be a polymorphic protein encoded by a gene with two codominant alleles, b1 and b2, at a locus. The tested population was found to be at Hardy-Weinberg equilibrium (chi2 = 0.834, p = 0.361), with only a minor heterozygote deficiency (fixation index F = 0.136). Since the histone H1.b alloforms were identified in a two-dimensional gel containing sodium dodecyl sulfate, with no significant differences in their migration pattern in an one-dimensional acetic acid polyacrylamide gel, we assumed that the H1.b alloforms possessed a similar net charge and differed in their apparent molecular weights. A comparison of N-bromosuccinimide-cleaved and alpha-chymotrypsin-digested products of histone H1.b alloforms revealed slight differences in the velocity of C-terminal peptides and a similarity in migration of their N-terminal peptides in one-dimensional sodium dodecyl sulfate-polyacrylamide gel. Therefore, it seemed that the histone H1.b alloforms might differ in this amino acid sequence in a protein segment between N-bromosuccinimide cleavage site and the very C-terminus.

Two polymorphic linker histone loci in Guinea fowl erythrocytes.

A variable migration of linker histone H1.b and H1.c spots in two-dimensional polyacrylamide gel patterns of total erythrocyte histone H1 has been detected during population screening in two differently plumaged Guinea fowl strains. Alloforms, H1.b1 and H1.b2 as well as H1.c1 and H1.c2, differing in apparent molecular weights tended to form only phenotypes b1 and b2 or c1 and c2 in a white-feathered strain while all phenotypes (b1, b2 and b1b2 or c1, c2 and c1c2, respectively) were present in a black-feathered population. Accordingly, the white-feathered population significantly deviated from the Hardy-Weinberg principle (chi-square test, d.f=1, p<<0.001) due to a lack of heterozygotes while the black-feathered population conformed to the Hardy-Weinberg equilibrium (p>0.05) at both H1.b and H1.c loci. Differential electrophoretic mobilities of the C-peptides from a partial chemical cleavage (N-bromosuccinimide) or limited enzymatic digestion (α-chymotrypsin and protease V8) of the histone H1.b and H1.c alloforms seem to indicate that altered amino acid sequence segments might be located either at the C-terminal end of globular domain or in the C-terminal domain itself.

Students of the Polish catholic theological seminars and the issue of organ transplantation.

BACKGROUND: The aim of the paper was the analysis of the stance and knowledge of the religious seminars alumni, about the legal foundations of transplantology. MATERIAL/METHODS: The study group were 204 alumni of the five senior religious seminars in Poland. By the use of an anonymous questionnaire, the clerics were interviewed. The questionnaire consisted of thirteen questions concerning the issue of organ transplants in Poland. RESULTS: It can be concluded that the attitude of clerics towards the organ transplantation is no different in principle from the attitude of the general public. Noteworthy is the fact that clerics often declared their consent to be donors of organs for transplantation. Attitudes of the clerics are also characterized by the fact that they did not object to procurement of organs of people close to them after their death. However, it can be concluded, that the attitude of surveyed clerics reflects a negative trend associated with a greater focus on receiving an organ in time of danger (95%), than the willingness to donating their organs after death (80%). CONCLUSIONS: The level of knowledge of the legal conditions of transplantation among the students of catholic seminars is increasing. Clerics are aware of the role of future educators, despite the fact that in majority of religious seminars there was no consent of the Deans to perform such survey.

Phenotypic variation of erythrocyte linker histone H1.c in a pheasant (Phasianus colchicus L.) population.

Our goal was to characterize a phenotypic variation of the pheasant erythrocyte linker histone subtype H1.c. By using two-dimensional polyacrylamide gel electrophoresis three histone H1.c phenotypes were identified. The differently migrating allelic variants H1.c1 and H1.c2 formed either two homozygous phenotypes, c1 and c2, or a single heterozygous phenotype, c1c2. In the pheasant population screened, birds with phenotype c2 were the most common (frequency 0.761) while individuals with phenotype c1 were rare (frequency 0.043).

Phenotypic variation of erythrocyte linker histone H1. c in a pheasant (Phasianus colchicus L.) population

Our goal was to characterize a phenotypic variation of the pheasant erythrocyte linker histone subtype H1.c. By using two-dimensional polyacrylamide gel electrophoresis three histone H1.c phenotypes were identified. The differently migrating allelic variants H1.c1 and H1.c2 formed either two homozygous phenotypes, c1 and c2, or a single heterozygous phenotype, c1c2. In the pheasant population screened, birds with phenotype c2 were the most common (frequency 0.761) while individuals with phenotype c1 were rare (frequency 0.043).

Linker histone-like proteins in Muscovy duck (Cairina moschata L) erythrocyte chromatin.

Linker Histone-Like proteins (LHL1 and LHL2) were identified within a linker histone complement of Muscovy duck erythrocyte chromatin. Polyacrylamide gel electrophoretic patterns of N-bromosuccinimide-cleaved LHL products as well as liquid chromatography-electrospray-ion trap mass spectrometry analyses of trypsin-digested LHL peptides revealed structural similarity of LHL1 to histone H5 and between LHL2 and histone H1 subtypes. Since the LHL proteins were stable in the presence of 2-mercaptoethanol and dithiothreitol that reduce disulfide bonds, it appeared unlikely that this doublet was a thiol-derived product of linker histones. A loss of LHL1, with a concomitant maintenance of LHL2 after treatment with dilute alkali, seems to suggest that they might represent disparate protein conjugates resulting from linker histone modifications through ester linkages.

Sequence variants of chicken linker histone H1.a.

Two allelic isoforms (H1.a1 and H1.a2) of histone H1.a were identified within two conservative flocks (R11 and R55) of Rhode Island Red chickens. These proteins form three phenotypes: a1, a2 and a1a2. Birds with phenotype a1 were most common (frequency 0.825-0.980) while the a1a2 chickens appeared relatively rarely (0.017-0.175). The third phenotype a2, not detected in the tested populations, has only been revealed in progeny of the purpose-mated a1a2 birds. The polymorphism of histone H1.a was observed in all examined chicken tissues, so that the H1 preparations isolated from the lung, spleen, kidney and testis from the same individual exhibited identical phenotypes (a1, a2, or a1a2). This finding, together with inheritance data, supports the genetic nature of the H1.a polymorphism. As indicated by cleavages with alpha-chymotrypsin and protease V8, the H1.a1 and H1.a2 are two highly related proteins which differ within N-terminal part of their C-terminal tails. Only a single nonconservative amino acid substitution between both H1.a allelic isoforms was detected by Edman degradation: glutamic acid present at position 117 in histone H1.a1 was replaced by lysine in histone H1.a2. Furthermore, using microsequencing techniques we have found a sequence homology between the N- and C-terminal parts of an unknown minor protein H1.y, present in the phenotype a2, and similar regions of histone H1.b.