The Morphology of the Thallus and Cupules of Blasia pusilla

First mention of the genus Blasia was made by Micheli Nov. Pl. Gen. 1729. Linnaeus recognized the genus and added the specific name pusilla in his Species Plantarum 1753 p. 1138. In 1759 Schmidel wrote his \u27\u27Dissertatio de Blasia.\u27\u27 Hooker 1816 called the plant Jungermannia blasia but as this classification is much too broad it is not used today. Gottsche 1828 published an account of the germination of the spores of Blasia piusilla. Later Grönland published his investigations of spore germination in the leafy Jungermanniae, including Blasia in his discussion. In 1833, Nees von Esenbeck made some investigations on vegetative propagation and erroneously stated that the bud-receptacles (cupules) of Blasia are closed when young and open at the top at a later period. An incorrect figure of Hedwig\u27s had probably given rise to this error. Hofmeister included in his work on The Higher Crytogamia, a short sketch of vegetative reproduction in Blasia, but some of his views are probably as faulty as those of Nees von Esenbeck

Molecular Investigation of the Distribution of Typhlatya spp. in Cave Systems Within the Yucatán Peninsula, Mexico

Stygobitic species such as the anchialine cave shrimp Typhlatya have adapted to life in freshwater and marine cave systems around the world. Limited research has been conducted on the ecological, morphological and genetic diversity of the four known species of the Yucatán Peninsula, Mexico: T. dzilamensis, T. pearsei, T. mitchelli and T. campecheae. A total of eighteen specimens were obtained from Dr. Thomas Iliffe’s collection housed in the Marine Biospeleology Lab at Texas A&M University at Galveston, representing seven cave systems (Temple of Doom, Systema Paamul, Carwash, Crustacea, Nayah, Sabak Ha, and Kankirixche). Specimens were photo-documented and identified to species level following diagnostic characters published in the taxonomic literature. Both the 16S rRNA and the nuclear internal transcribed spacer (ITS) gene were sequenced. After analyzing the sequences, phylogenetic trees and genetic distance tables were generated to discern the phylogenetic relationship among the specimens and compared to our initial morphological diagnosis. The phylogenetic analyses of 16S showed five distinct clades: T. dzilamensis, T. mitchelli A and B, T. pearsei, and Typhlatya sp. Data acquired from this study will be part of a larger study that will provide more insight into the biogeography and connectivity of cave systems within the Yucatán Peninsula.

Academic Senate - Meeting Minutes, 4/18/2017

<p>All values are presented with SD. Differences between <i>LDLR−/−</i> and the other two genotypes are significant where indicated, ANOVA: *p<0.05, **p<0.01.</p

A Dystrophin Exon-52 Deleted Miniature Pig Model of Duchenne Muscular Dystrophy and Evaluation of Exon Skipping

Duchenne muscular dystrophy (DMD) is a lethal X-linked recessive disorder caused by mutations in the DMD gene and the subsequent lack of dystrophin protein. Recently, phosphorodiamidate morpholino oligomer (PMO)-antisense oligonucleotides (ASOs) targeting exon 51 or 53 to reestablish the DMD reading frame have received regulatory approval as commercially available drugs. However, their applicability and efficacy remain limited to particular patients. Large animal models and exon skipping evaluation are essential to facilitate ASO development together with a deeper understanding of dystrophinopathies. Using recombinant adeno-associated virus-mediated gene targeting and somatic cell nuclear transfer, we generated a Yucatan miniature pig model of DMD with an exon 52 deletion mutation equivalent to one of the most common mutations seen in patients. Exon 52-deleted mRNA expression and dystrophin deficiency were confirmed in the skeletal and cardiac muscles of DMD pigs. Accordingly, dystrophin-associated proteins failed to be recruited to the sarcolemma. The DMD pigs manifested early disease onset with severe bodywide skeletal muscle degeneration and with poor growth accompanied by a physical abnormality, but with no obvious cardiac phenotype. We also demonstrated that in primary DMD pig skeletal muscle cells, the genetically engineered exon-52 deleted pig DMD gene enables the evaluation of exon 51 or 53 skipping with PMO and its advanced technology, peptide-conjugated PMO. The results show that the DMD pigs developed here can be an appropriate large animal model for evaluating in vivo exon skipping efficacy

An integrative re-evaluation of Typhlatya shrimp within the karst aquifer of the Yucatan Peninsula, Mexico

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ballou, L., Brankovits, D., Chavez-Solis, E. M., Diaz, J. M. C., Gonzalez, B. C., Rohret, S., Salinas, A., Liu, A., Simoes, N., Alvarez, F., Miglietta, M. P., Iliffe, T. M., & Borda, E. An integrative re-evaluation of Typhlatya shrimp within the karst aquifer of the Yucatan Peninsula, Mexico. Scientific Reports, 12(1), (2022): 5302, https://doi.org/10.1038/s41598-022-08779-9.The Yucatán Peninsula, Mexico is a carbonate platform well-known for extensive karst networks of densely stratified aquifer ecosystems. This aquifer supports diverse anchialine fauna, including species of the globally distributed anchialine shrimp genus Typhlatya (Atyidae). Four species (T. campecheae, T. pearsei, T. dzilamensis and T. mitchelli) are endemic to the Peninsula, of which three are federally listed in Mexico. This first integrative evaluation (i.e., molecular, morphological, broad geographic and type locality sampling, and environmental data) of Yucatán Typhlatya reveals considerable species identity conflict in prior phylogenetic assessments, broad species ranges, syntopy within cave systems and five genetic lineages (of which two are new to science). Despite sampling from the type locality of endangered T. campecheae, specimens (and molecular data) were indistinguishable from vulnerable T. pearsei. Ancestral/divergence reconstructions support convergent evolution of a low-salinity ancestor for a post-Paleogene arc Yucatán + Cuba Typhlatya clade within the anchialine Atyidae clade. A secondary adaptation for the coastal-restricted euryhaline (2–37 psu), Typhlatya dzilamensis (unknown conservation status) was identified, while remaining species lineages were low-salinity (< 5 psu) adapted and found within the meteoric lens of inland and coastal caves. This study demonstrates the need for integrative/interdisciplinary approaches when conducting biodiversity assessments in complex and poorly studied aquifers.Financial support for this study was provided by Texas A&M-CONACYT (TI, FA), TI, FA), PAPIIT IN208519 (DGAPA-UNAM) (FA), CONACYT Ciencia Básica A1-S-32846 (FA), Texas A&M University San Antonio (TAMUSA) Start-up Funds (EB), TAMUSA Research Council Grant (EB), TAMUSA Summer Faculty Grant and Fellowship (EB). NSF-REU/OCE: 1560242 supported AL and EB, and TAMU-Louis Stokes Alliance for Minority Participation (HRD: 1612776) supported SR, LS. This work was also supported by the NSF Graduate Research Fellowship Program (M1703014) and the Cave Conservancy Foundation (LB). Typhlatya sampling was sanctioned under collection permits SEMARNAT/SGPA/DGVS 05263/14, 004471/18, 05996/19

Structural geology of the Bishop Cap Hills in south-central New Mexico

The Bishop Cap Hills (BCH) of south-central New Mexico consist of deformed Ordovician and Pennsylvanian sedimentary rocks. Structures in the BCH record Laramide shortening and Rio Grande Rift extension. This deformation history has been analyzed using the geometry and field relations of faults, veins, and folds. Numerous well-preserved normal faults and fewer poorly-preserved reverse faults have slickensides, tool marks, and fibrous veins on their surfaces which are inferred to parallel directions of maximum shear strain rate. Orientations of these lineations on fault planes are used in a quantitative kinematic analysis that yields the orientations of the principal incremental strain axis. In addition, Laramide folding of Paleozoic strata, and veins created from rifting and local caldera activity, have distinct geometries which place constraints on the deformation history. Absolute ages of rock units, cross-cutting relations of faults and veins, and retro-deformation of stereonet data define a sequential history as follows: (1) NE directed Laramide shortening recorded by folds and reverse faults; (2) Early veins consistent with NNE oriented extension; (3) NE directed extension indicated by normal faults that cut the BCH into tilted blocks; and (4) NNW extension dated at 5.43 ± 0.34 Ma. This data shows that Rio Grande Rift extension in the BCH has been heterogeneous and involved components of NE and nearly N-S extension. These nearly orthogonal extension directions are consistent with finite radial horizontal extension. This pattern of extension can be explained by vertical shortening or magmatic inflation of the crust if assumed to represent a single progressive deformation

Abdominal Aortic Atherosclerosis from 11-month old <i>LDLR+/+, LDLR+/−</i>, and <i>LDLR−/−</i> pigs fed a high fat, high cholesterol diet.

<p>All values are presented with SD. Differences between <i>LDLR−/−</i> and the other two genotypes are significant where indicated, ANOVA: **p<0.01.</p

Summary of total cholesterol from <i>LDLR+/+</i>, <i>LDLR+/−</i>, and <i>LDLR−/−</i> pigs fed a high fat, high cholesterol diet for 90 and 180 days.

<p>All values are presented with SD. Differences between <i>LDLR+/+</i> and <i>LDLR+/−</i> are significant where indicated, ANOVA: *p<0.05, **p<0.01. Differences between <i>LDLR−/−</i> and the other two genotypes are significant where indicated, ANOVA: **p<0.01.</p

Summary of <i>LDLR</i> gene targeting and SCNT activity.

<p>*Gene targeting efficiency reported as percentage of G418^R clones that were properly targeted, as determined by PCR.</p>†<p>Pregnancy rate refers to full-term gestation.</p

Molecular and biochemical characterization of <i>LDLR+/+</i>, <i>LDLR+/−</i>, and <i>LDLR−/−</i> pigs.

<p>A. Genotyping by PCR. Expected sizes are 1.5-type <i>LDLR</i> and 3.2 kb for targeted <i>LDLR</i>. B. Southern blot of genomic DNA. (Left) <i>XmnI</i> digested genomic DNA was hybridized with a probe that detects porcine <i>LDLR</i> downstream of the targeting vector boundary. The <i>LDLR</i>-targeted allele produced an approximately 7.8 kb band, and the wild-type band is approximately 6.0 kb. (Right) The same DNA was hybridized with a probe that detects the <i>Neo^R</i> cassette, yielding only the targeted 7.8 kb band. C. Northern blot of <i>LDLR</i> and <i>GAPDH</i> mRNA. Full-length <i>LDLR</i> and <i>GAPDH</i> mRNAs are 5.1 and 1.5 kb, respectively. The asterisk represents a minor mRNA species consisting of full-length <i>LDLR</i> mRNA plus the <i>Neo^R</i> cassette. The bracket indicates two minor mRNA species that are likely the result of nonsense-mediated mRNA altered splicing. D. Representative RT-PCR. Using PCR primers that amplify from exon 1 to exon 5, the targeted <i>LDLR</i> allele produces no normal mRNA, but does produce mRNA species with deletions of exon 4 or exons 3 and 4. This is seen in both the <i>LDLR+/−</i> and <i>LDLR−/−</i> pigs. This result was confirmed by DNA sequencing. E. Representative western blot of LDLR and β-tubulin. LDLR is ∼150 kDa and β-tubulin is 51 kDa.</p