Convergence of forelimb afferent actions on C7-Th1 propriospinal neurones bilaterally projecting to sacral segments of the cat spinal cord

Propriospinal neurones located in the cervical enlargement and projecting bilaterally to sacral segments of the spinal cord were investigated electrophysiologically in eleven deeply anaesthetized cats. Excitatory or inhibitory postsynaptic potentials from forelimb afferents were recorded following stimulation of deep radial (DR), superficial radial (SR), median (Med) and ulnar (Uln) nerves. 26 cells were recorded from C7, 22 from C8 and 3 from Th1 segments. The majority of the cells were located in the Rexed's laminae VIII and the medial part of the lamina VII. In 10 cases no afferent input from the forelimb afferents was found. In the remaining neurones effects were evoked mostly from DR (88%) and Med (63%), less often from SR (46%) and Uln (46%). Inhibitory actions were more frequent than excitatory. The highest number of IPSPs was evoked from high threshold flexor reflex afferents (FRA)--all connections were polysynaptic. However, inhibitory actions were often evoked from group I or II muscle afferents (polysynaptic or disynaptic) and, less frequently, from cutaneous afferents (mostly polysynaptic). Di- or polysynaptic IPSPs often accompanied monosynaptic EPSPs from group I or II muscle afferents. Disynaptic or polysynaptic EPSPs from muscle and cutaneous afferents were also recorded in many neurones, while polysynaptic EPSPs from FRA were observed only exceptionally. Various patterns of convergence in individual neuronal subpopulations indicate that they integrate different types of the afferent input from various muscle and cutaneous receptors of the distal forelimb. They transmit this information to motor centers controlling hind limb muscles, forming a part of the system contributing to the process of coordination of movements of fore--and hind--limbs.     

Comparative Genomics of Marine Mussels (Mytilus spp.) Gender Associated mtDNA: Rapidly Evolving atp8

The unusual mode of mitochondrial DNA inheritance, with two separate: maternal (F) and paternal (M) lineages, gives unique opportunities to study the evolution of the mitochondrial genome. This system was first discovered in the marine mussels Mytilus. The three related species: Mytilus edulis, Mytilus galloprovincialis and Mytilus trossulus form a complex in which the divergence of M and F lineages pre-dates the speciation. The complete mitochondrial genomes of both lineages were known for all species except Pacific M. trossulus. Here we report, for the first time, the complete sequences of both mitochondrial genomes of Pacific M. trossulus, filling the gap. While the reported M and F genomes are highly diverged (26%), they have similar organisation. The only difference is the translocation of one tRNA gene into the long, mosaic control region of the F genome. Consistent presence of an ORF which most likely represents the atp8 gene was confirmed in both genomes. The predicted protein has characteristics expected of the functional atp8 even though the M and F versions are markedly different in length. Comparative analysis involving all three species led to the conclusion that the cause of a faster evolution of atp8 and Mytilus mtDNA in general is most likely the Compensation-Draft Feedback process coupled with relatively relaxed selection in the M lineage. Thus, we postulate that the adaptive changes may have played a role in the emergence of highly diverged, barely recognizable atp8 in Mytilus mussels.     

Quantitative analysis of mRNA expression levels and DNA methylation profiles of three neighboring genes: FUS1, NPRL2/G21 and RASSF1A in non-small cell lung cancer patients

Background

Tumor suppressor gene (TSG) inactivation plays a crucial role in carcinogenesis. FUS1, NPRL2/G21 and RASSF1A are TSGs from LUCA region at 3p21.3, a critical chromosomal region in lung cancer development. The aim of the study was to analyze and compare the expression levels of these 3 TSGs in NSCLC, as well as in macroscopically unchanged lung tissue surrounding the primary lesion, and to look for the possible epigenetic mechanism of TSG inactivation via gene promoter methylation.

Methods

Expression levels of 3 TSGs and 2 DNA methyltransferases, DNMT1 and DNMT3B, were assessed using real-time PCR method (qPCR) in 59 primary non-small cell lung tumors and the matched macroscopically unchanged lung tissue samples. Promoter methylation status of TSGs was analyzed using methylation-specific PCRs (MSP method) and Methylation Index (MI) value was calculated for each gene.

Results

The expression of all three TSGs were significantly different between NSCLC subtypes: RASSF1A and FUS1 expression levels were significantly lower in squamous cell carcinoma (SCC), and NPRL2/G21 in adenocarcinoma (AC). RASSF1A showed significantly lower expression in tumors vs macroscopically unchanged lung tissues. Methylation frequency was 38–76 %, depending on the gene. The highest MI value was found for RASSF1A (52 %) and the lowest for NPRL2/G21 (5 %). The simultaneous decreased expression and methylation of at least one RASSF1A allele was observed in 71 % tumor samples. Inverse correlation between gene expression and promoter methylation was found for FUS1 (rs = −0.41) in SCC subtype. Expression levels of DNMTs were significantly increased in 75–92 % NSCLCs and were significantly higher in tumors than in normal lung tissue. However, no correlation between mRNA expression levels of DNMTs and DNA methylation status of the studied TSGs was found.

Conclusions

The results indicate the potential role of the studied TSGs in the differentiation of NSCLC histopathological subtypes. The significant differences in RASSF1A expression levels between NSCLC and macroscopically unchanged lung tissue highlight its possible diagnostic role in lung cancer in situ recognition. High percentage of lung tumor samples with simultaneous RASSF1A decreased expression and gene promoter methylation indicates its epigenetic silencing. However, DNMT overexpression doesn’t seem to be a critical determinate of its promoter hypermethylation.     

Combined molecular and morphological data provide insights into the evolution and classification of Chilocorini ladybirds (Coleoptera: Coccinellidae)

Ladybirds of the cosmopolitan tribe Chilocorini prey mainly on coccids and include several important biocontrol agents. The phylogenetic relationships of Chilocorini are poorly known. In this paper, we provide a phylogenetic reconstruction of Chilocorini containing all 27 genera based on five molecular markers and 86 adult morphological characters. Morphological character states were mapped on the combined data tree from Bayesian inference to analyse morphological traits of each genus. Sixteen morphological characters were selected to reconstruct the ancestral states using maximum parsimony and maximum likelihood methods. Divergence times were estimated based on the relaxed molecular clock approach. Our results indicate that Chilocorini, excluding Chilocorellus Miyatake, is monophyletic and closely related to Plotinini. The crown group Chilocorini was estimated to date back to the Middle Cretaceous. Anisorcus Crotch, Egius Mulsant, Phaenochilus Weise and Simmondsius Ahmad & Ghani are synonymized here with Chilocorus Leach ( syn.n. ). The genus Chilocorellus is excluded from Chilocorini. The split of current genera was estimated to have occurred during the Middle Paleogene to Late Paleogene.     

Molecular profile of the NF‐κB signalling pathway in human colorectal cancer

The development and progression of colorectal cancer (CRC) have been associated with inflammation processes that involve the overactivation of the NF‐κB signalling pathway. The characterization of the NF‐κB expression profile in CRC is an important topic since the suppression of NF‐κB represents a potential therapeutic approach. In this study, we assessed the expression levels of 84 NF‐κB‐related genes in paired tumoral (T) and peritumoral (PT) tissues from 18 CRC patients and 18 normal colonic mucosae, and the expression levels of three miRNAs targeting the most dysregulated genes revealed by the case–control analysis. Comparing the gene expression profile of T and controls, 60 genes were dysregulated. The comparison of T and PT revealed 17 dysregulated genes in the tumoral tissues, with IL1B, CXCL8, IL1A, and CSF2 being the most upregulated. Notably, through a bioinformatics analysis, the differential gene expression of 11 out of the 17 genes was validated on a larger cohort of 308 CRC patients compared with 41 controls. Moreover, a decrease in the levels of RELA, NOD1, CASP8, BCL2L1, ELK1, and IKBKB was identified in poorly differentiated tumours compared to moderately differentiated tumours. The analysis of the three miRNAs targeting IL1B, CXCL8, IL1A, and CSF2 showed that miR‐182‐5p was upregulated in T compared with PT, whereas miR‐10b‐5p was downregulated in T compared with PT and control tissues. Our results may contribute to the design of new experimental therapeutic strategies based on endogenous molecules, such as miRNAs, to target the genetic key players of the NF‐ κB pathway.     

Variability and structure of natural populations of Hordelymus europaeus (L.) Jess. ex Harz and Leymus arenarius (L.) Hochst. as revealed by morphology and DNA markers

Seven populations of Hordelymus europaeus and four populations of Leymus arenarius from Poland were subjected to examination of 36 morphological characters. This study showed that both species are relatively uniform and that morphological variation of their populations represents a continuum. Of those, three populations of either species were selected for analysis with molecular markers – RAPDs and AFLPs. These populations differed with respect of geographical location as well as syntaxa and habitat. RAPD-PCR was performed for individual plants and clearly grouped them according to the population origin. For either H. europaeus or L. arenarius - the studied populations differed in degree of their intrinsic variation while none of them as a whole was significantly different from the remaining ones. In AFLP analysis the studied populations were represented by DNA pools of several individual plants. Also this approach allowed discrimination among the population samples of both H. europaeus and L. arenarius. Both RAPDs and AFLPs were accordant in indication that H. europaeus exceeds L. arenarius with respect to variation accumulated at the DNA level. It is the sixth paper of the series: Biodiversity of wild Triticeae (Poaceae) in Poland. The first is: M. Mizianty (2005). Variability and structure of natural populations of Elymus caninus (L.) L. based on morphology. Pl. Syst. Evol. 251: 199-216. The second: M. Mizianty, and M. Szklarczyk (2005). Systematic significance of Elymus caninus morphological characters revealed by AFLP analysis. In: L. Frey (ed.) Biology of grasses. W. Szafer Institute of Botany, Polish Academy of Sciences. Kraków, pp 9–21. The third: M. Mizianty et al. (2006). Variability and structure of natural populations of Elymus caninus (L.) L. and their possible relationship with Hordelymus europaeus (L.) Jess. ex Harz revealed by AFLP analysis. Pl. Syst. Evol. 256: 193–200. The fourth: M. Mizianty (2006). Variability and structure of natural populations of Hordeum murinum L. based on morphology. Pl. Syst. Evol. 261: 139–150. The fifth: B. Paszko Variability and structure of natural populations of Brachypodium pinnatum and B. sylvaticum based on morphology. Acta Soc. Bot. Pol. (in press).     

Coexpression of vimentin and desmin in gastric leiomyomas. An immunohistochemical study in paraffin sections

The aim of the study was to evaluate the incidence of the reactions for vimentin and desmin in gastric leiomyomas routinely processed in formalin and embedded i paraffin. The material studied included four benign leiomyomas, seven malignant leiomyomas and three malignant epithelioid leiomyomas. A positive reaction to vimentin was found in 13 out 14 leiomyomas under study. The number of neoplastic cells showing vimentin expression was larger in malignant, especially epithelioid leiomyomas than in non-malignant leiomyomas. A positive reaction for desmin in neoplastic cells was found in 9 leiomyomas 64%. One non-malignant leiomyoma showed a moderate reaction. In the remaining eight cases the reaction was weak and occurred in single neoplastic cells. Coexpression of vimentin and desmin in neoplastic cells occurred in 8 out of 9 leiomyomas with a positive reaction for desmin. Coexpression of vimentin and desmin occurred also in the smooth muscle cells of blood vessels in all 14 cases. A weak reaction for desmin or its lack in the tumour cells of leiomyomas with its marked expression in the smooth muscle cells of the blood vessels and gastric wall outside the tumor points rather to a small number of desmin filaments in the neoplastic cells than to their destruction by fixation in formalin. The occurrence of the reaction to desmin only in a limited number of neoplastic cells questions the reliability of its use in the oligopiopsy material.