Three SRA-Domain Methylcytosine-Binding Proteins Cooperate to Maintain Global CpG Methylation and Epigenetic Silencing in Arabidopsis

Methylcytosine-binding proteins decipher the epigenetic information encoded by DNA methylation and provide a link between DNA methylation, modification of chromatin structure, and gene silencing. VARIANT IN METHYLATION 1 (VIM1) encodes an SRA (SET- and RING-associated) domain methylcytosine-binding protein in Arabidopsis thaliana, and loss of VIM1 function causes centromere DNA hypomethylation and centromeric heterochromatin decondensation in interphase. In the Arabidopsis genome, there are five VIM genes that share very high sequence similarity and encode proteins containing a PHD domain, two RING domains, and an SRA domain. To gain further insight into the function and potential redundancy among the VIM proteins, we investigated strains combining different vim mutations and transgenic vim knock-down lines that down-regulate multiple VIM family genes. The vim1 vim3 double mutant and the transgenic vim knock-down lines showed decreased DNA methylation primarily at CpG sites in genic regions, as well as repeated sequences in heterochromatic regions. In addition, transcriptional silencing was released in these plants at most heterochromatin regions examined. Interestingly, the vim1 vim3 mutant and vim knock-down lines gained ectopic CpHpH methylation in the 5S rRNA genes against a background of CpG hypomethylation. The vim1 vim2 vim3 triple mutant displayed abnormal morphological phenotypes including late flowering, which is associated with DNA hypomethylation of the 5′ region of FWA and release of FWA gene silencing. Our findings demonstrate that VIM1, VIM2, and VIM3 have overlapping functions in maintenance of global CpG methylation and epigenetic transcriptional silencing

Mesenchymal Stem Cells Promote Mammosphere Formation and Decrease E-Cadherin in Normal and Malignant Breast Cells

Normal and malignant breast tissue contains a rare population of multi-potent cells with the capacity to self-renew, referred to as stem cells, or tumor initiating cells (TIC). These cells can be enriched by growth as "mammospheres" in three-dimensional cultures.We tested the hypothesis that human bone-marrow derived mesenchymal stem cells (MSC), which are known to support tumor growth and metastasis, increase mammosphere formation.We found that MSC increased human mammary epithelial cell (HMEC) mammosphere formation in a dose-dependent manner. A similar increase in sphere formation was seen in human inflammatory (SUM149) and non-inflammatory breast cancer cell lines (MCF-7) but not in primary inflammatory breast cancer cells (MDA-IBC-3). We determined that increased mammosphere formation can be mediated by secreted factors as MSC conditioned media from MSC spheroids significantly increased HMEC, MCF-7 and SUM149 mammosphere formation by 6.4 to 21-fold. Mammospheres grown in MSC conditioned media had lower levels of the cell adhesion protein, E-cadherin, and increased expression of N-cadherin in SUM149 and HMEC cells, characteristic of a pro-invasive mesenchymal phenotype. Co-injection with MSC in vivo resulted in a reduced latency time to develop detectable MCF-7 and MDA-IBC-3 tumors and increased the growth of MDA-IBC-3 tumors. Furthermore, E-cadherin expression was decreased in MDA-IBC-3 xenografts with co-injection of MSC.MSC increase the efficiency of primary mammosphere formation in normal and malignant breast cells and decrease E-cadherin expression, a biologic event associated with breast cancer progression and resistance to therapy

LITTLE NUCLEI Genes Affecting Nuclear Morphology in Arabidopsis thaliana[W]

Efforts to understand nuclear organization in plant cells have received little assistance from the better-studied animal nuclei, because plant proteomes do not contain recognizable counterparts to the key animal proteins involved in nuclear organization, such as lamin nuclear intermediate filament proteins. Previous studies identified a plant-specific insoluble nuclear protein in carrot (Daucus carota), called Nuclear Matrix Constituent Protein1 (NMCP1), which contains extensive coiled-coil domains and localizes to the nuclear periphery. Here, we describe a genetic characterization of two NMCP1-related nuclear proteins in Arabidopsis thaliana, LITTLE NUCLEI1 (LINC1) and LINC2. Disruption of either gene caused a reduction in nuclear size and altered nuclear morphology. Moreover, combining linc1 and linc2 mutations had an additive effect on nuclear size and morphology but a synergistic effect on chromocenter number (reduction) and whole-plant morphology (dwarfing). The reduction in nuclear size in the linc1 linc2 double mutant was not accompanied by a corresponding change in endopolyploidy. Rather, the density of DNA packaging at all endopolyploid levels in the linc1 linc2 mutants was increased significantly. Our results indicate that the LINC coiled-coil proteins are important determinants of plant nuclear structure

Phylogenetic structure of Holbrookia lacerata (Cope 1880) (Squamata: Phrynosomatidae): one species or two?

Hibbitts, Toby J., Ryberg, Wade A., Harvey, Johanna A., Voelker, Gary, Lawing, A. Michelle, Adams, Connor S., Neuharth, Dalton B., Dittmer, Drew E., Duran, C. Michael, Wolaver, Brad D., Pierre, Jon Paul, Labay, Benjamin J., Laduc, Travis J. (2019): Phylogenetic structure of Holbrookia lacerata (Cope 1880) (Squamata: Phrynosomatidae): one species or two? Zootaxa 4619 (1): 139-154, DOI: 10.11646/zootaxa.4619.1.

Holbrookia subcaudalis

Holbrookia subcaudalis (Axtell 1956) Tamaulipan Spot-tailed Earless Lizard (Fig. 9) Holbrookia lacerata subcaudalis Axtell 1956 Holbrookia subcaudalis Hibbitts et al. 2019 (this study) Holotype. Texas Natural History Collection, University of Texas (TNHC 20000); collected by Ralph W. Axtell on 6 June 1955 in plowed field 4.8 miles east northeast of Bishop, Nueces County, Texas, USA (27º 36’ N; 97º 45’ W) at an elevation of 75 feet. Etymology. The name subcaudalis is derived from the latin word sub which means under or below and cauda which means tail. This refers to the dark spots on the underside of the tail in this species. Distribution. Holbrookia subcaudalis is composed of all populations south of the Balcones Escarpment in Texas and west to the Sierra Madre Oriental in Coahuila, Nuevo Leon, and Tamaulipas, Mexico. They are absent from areas with sandy soils. Diagnosis. Morphological description based on measurements and counts from 45 adults. This is a small, earless lizard with an average of 5 (1 – 10) black spots on the underside of the tail. The average snout-vent length (SVL) is 56 mm (31 – 72), paravertebral and dorsolateral body blotches are often separated. An average of 0.7 (0 – 6) blotches are fused out of an average of 6 (4 – 9) blotches. The blotches form four rows of transverse mostly circular blotches. The dark blotches on the rear legs are circular in shape and do not form into bands with the average number of leg blotches being 8 (4 – 14). Most individuals have black lateral spots on the abdomen and these average 2.6 (0 – 5). The average number of femoral pores on the left leg is 14 (10 – 19). The female body color is greenish yellow during the breeding season but they do not acquire orange on the throat in either sex.Published as part of Hibbitts, Toby J., Ryberg, Wade A., Harvey, Johanna A., Voelker, Gary, Lawing, A. Michelle, Adams, Connor S., Neuharth, Dalton B., Dittmer, Drew E., Duran, C. Michael, Wolaver, Brad D., Pierre, Jon Paul, Labay, Benjamin J. & Laduc, Travis J., 2019, Phylogenetic structure of Holbrookia lacerata (Cope 1880) (Squamata: Phrynosomatidae): one species or two?, pp. 139-154 in Zootaxa 4619 (1) on pages 148-149, DOI: 10.11646/zootaxa.4619.1.6, http://zenodo.org/record/324848

Spindle cell morphology is related to poor prognosis in vulvar squamous cell carcinoma

BACKGROUND: Vulvar cancer is the fourth most common gynaecological malignancy, with an annual incidence of 2 out of 100 000 women. Although most cases of early stage vulvar cancer have a good prognosis, recurrence and rapid tumour progression can occur. We investigated the prevalence of spindle cell morphology in vulvar cancer and its association with survival. METHODS: This retrospective cohort study included 108 patients with primary vulvar squamous cell carcinoma who were treated at the Leiden University Medical Center during 2000–2009. Paraffin-embedded tissue was examined for the presence of spindle cell morphology. Survival and histology data were compared between cases with spindle and without spindle cell morphology. RESULTS: Twenty-two (20%) tumours showed spindle cells infiltrating the stromal tissue. All spindle cell tumours were human papillomavirus (HPV) negative. Spindle cell morphology was strongly associated with poor prognosis and with a high risk of lymph node involvement at the time of diagnosis (relative risk 2.26 (95% CI 1.47–3.47)). Five-year disease-specific survival was lower in patients with vs without spindle cell morphology (45.2% vs 79.7%, respectively; P=0.00057). CONCLUSION: Vulvar spindle cell morphology occurs frequently and seems to develop through the non-HPV pathway. It is associated with a worse prognosis than conventional vulvar squamous cell carcinoma