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Increasing amounts of data support a role for guanine quadruplex (G4) DNA and RNA structures in various cellular processes. We stained different organisms with monoclonal antibody 1H6 specific for G4 DNA. Strikingly, immuno-electron microscopy showed exquisite specificity for heterochromatin. Polytene chromosomes from Drosophila salivary glands showed bands that co-localized with heterochromatin proteins HP1 and the SNF2 domain-containing protein SUUR. Staining was retained in SUUR knock-out mutants but lost upon overexpression of SUUR. Somatic cells in Macrostomum lignano were strongly labeled, but pluripotent stem cells labeled weakly. Similarly, germline stem cells in Drosophila ovaries were weakly labeled compared to most other cells. The unexpected presence of G4 structures in heterochromatin and the difference in G4 staining between somatic cells and stem cells with germline DNA in ciliates, flatworms, flies and mammals point to a conserved role for G4 structures in nuclear organization and cellular differentiation.

Genetic modification of cells and animals is an invaluable tool for biotechnology and biomedicine. Currently, integrating vectors are used for this purpose. These vectors, however, may lead to insertional mutagenesis and variable transgene expression and can undergo silencing. Scaffold/matrix attachment region-based vectors are nonviral expression systems that replicate autonomously in mammalian cells, thereby making possible safe and reliable genetic modification of higher eukaryotic cells and organisms. In this study, genetically modified pig fetuses were produced with the scaffold/matrix attachment region-based vector pEPI, delivered to embryos by the sperm-mediated gene transfer method. The pEPI vector was detected in 12 of 18 fetuses in the different tissues analyzed and was shown to be retained as an episome. The reporter gene encoded by the pEPI vector was expressed in 9 of 12 genetically modified fetuses. in positive animals, all tissues analyzed expressed the reporter gene; moreover in these tissues, the positive cells were on the average 79%. The high percentage of EGFP-expressing cells and the absence of mosaicism have important implications for biotechnological and biomedical applications. These results are an important step forward in animal transgenesis and can provide the basis for the future development of germ-line gene therapy.

The 2013 nesting season was the second year comparing the Peterson box to the traditional rectangular blue bird nesting box. Peterson boxes have a lower internal volume, requiring less material and parental effort for nest construction. It has been suggested that by freeing up energy for rearing young, fledging success could be improved over that of the traditional box. As during the previous season, bluebirds, tree swallows and chickadees utilized the Peterson boxes. However, unlike the 2012 season, more nests were built in Peterson boxes than in the traditional boxes. Of the 11 nests built in Peterson boxes, eggs were laid in 8 boxes of which only 4 successfully fledged chicks. Eggs or chicks were lost to predators from 3 of the Peterson boxes, while one clutch of 3 chicks was found dead in the nest. Five nests were built in traditional boxes, of which three fledged chicks. Hatching and fledging success were higher for eggs laid in traditional boxes than in the Peterson boxes. However, the paucity of clutches (2 of the 3 clutches in traditional boxes were in the same box) makes it difficult to draw a conclusion about hatching of fledging success. Student volunteers from both the general biology and human anatomy and physiology classes at Mountain Empire Community College assisted in the monitoring of nesting activity during the course of the breeding season, as well as maintenance along the trail.

The 2013 nesting season was the second year comparing the Peterson box to the traditional rectangular blue bird nesting box. Peterson boxes have a lower internal volume, requiring less material and parental effort for nest construction. It has been suggested that by freeing up energy for rearing young, fledging success could be improved over that of the traditional box. As during the previous season, bluebirds, tree swallows and chickadees utilized the Peterson boxes. However, unlike the 2012 season, more nests were built in Peterson boxes than in the traditional boxes. Of the 11 nests built in Peterson boxes, eggs were laid in 8 boxes of which only 4 successfully fledged chicks. Eggs or chicks were lost to predators from 3 of the Peterson boxes, while one clutch of 3 chicks was found dead in the nest. Five nests were built in traditional boxes, of which three fledged chicks. Hatching and fledging success were higher for eggs laid in traditional boxes than in the Peterson boxes. However, the paucity of clutches (2 of the 3 clutches in traditional boxes were in the same box) makes it difficult to draw a conclusion about hatching of fledging success. Student volunteers from both the general biology and human anatomy and physiology classes at Mountain Empire Community College assisted in the monitoring of nesting activity during the course of the breeding season, as well as maintenance along the trail.

We report the results of strange and light-quark hadron masses obtained by a simulation of QCD in the zero fermion loops approximation (quenching) on a 103 × 20 lattice. The results are sensibly different from those obtained on smaller lattices and show a definite improvement. © 1983.