Chinchilla "big" and "little" gastrins

Gastrin heptadecapeptides (gastrins I and II which differ in the presence of sulfate on the tyrosine of the latter) have been purified and sequenced from several mammalian species including pig, dog, cat, sheep, cow, human and rat. A 34 amino acid precursor ("big" gastrin), generally accounting for only 5% of total gastrin immunoreactivity, has been purified and sequenced only from the pig, human, dog and goat. Recently we have demonstrated that guinea pig (GP) "little" gastrin is a hexadecapeptide due to a deletion of a glutamic acid in the region 6-9 from its NH2-terminus and that GP "big" gastrin is a 33 amino acid peptide. The chinchilla, like the GP, is a New World hystricomorph. This report describes the extraction and purification of "little" and "big" gastrins from 31 chinchilla antra. Chinchilla "little" gastrin is a hexadecapeptide with a sequence identical to that of the GP and its "big" gastrin is a 33 amino acid peptide with the following sequence: (See text)     

CTG trinucleotide repeat "big jumps": large expansions, small mice

Trinucleotide repeat expansions are the genetic cause of numerous human diseases, including fragile X mental retardation, Huntington disease, and myotonic dystrophy type 1. Disease severity and age of onset are critically linked to expansion size. Previous mouse models of repeat instability have not recreated large intergenerational expansions ("big jumps"), observed when the repeat is transmitted from one generation to the next, and have never attained the very large tract lengths possible in humans. Here, we describe dramatic intergenerational CTG*CAG repeat expansions of several hundred repeats in a transgenic mouse model of myotonic dystrophy type 1, resulting in increasingly severe phenotypic and molecular abnormalities. Homozygous mice carrying over 700 trinucleotide repeats on both alleles display severely reduced body size and splicing abnormalities, notably in the central nervous system. Our findings demonstrate that large intergenerational trinucleotide repeat expansions can be recreated in mice, and endorse the use of transgenic mouse models to refine our understanding of triplet repeat expansion and the resulting pathogenesis.     

Reproductive biotechnology and "big" biological questions

In recent decades, scientists have learned to manipulate that cardinal characteristic of life, reproduction, with powerful techniques like artificial insemination, contraception, embryo transfer, cryopreservation, and cloning by nuclear transfer. While these technologies often are used for practical applications and basic research, they have another profound intrinsic quality, which is to engender deep-seated thinking about important biological questions. Examples that stimulate such thinking include a goat's giving birth to her identical twin sister via splitting embryos, cryopreservation, and embryo transfer; that a parthenogenetic embryo can never become an animal but can become a genetic mother via an aggregation chimera; or that a somatic cell can become the sole genetic parent of a calf via cloning. In this paper, I illustrate this thought-stimulating quality by considering contributions of reproductive technologies to understanding, if not completely answering, several important biological questions.     

Opossum (Didelphis virginiana) "little" and "big" gastrins

1. "Little" gastrins from most mammalian species are 17 amino acid peptides and the precursor "big" gastrins are 34 amino acid peptides. 2. "Little" gastrins of the New World hystricomorphs, guinea-pig and chinchilla, are 16 amino acid peptides due to deletion of a glutamic acid in the region 6-9 from their NH2-terminus and the corresponding "big" gastrins are 33 amino acid peptides. 3. Antral gastrins from the opossum, a New World marsupial, have a glutamic acid deletion in the same region as the hystricomorph gastrins. 4. Opossum "big" gastrin is a 33 amino acid peptide with the following sequence: less than ELGPQDLPYLTADLSKKQGPWLEEEEAYGWMDF#.     

The central image makes "big" dreams big: The central image as the emotional heart of the dream.

"Big dreams" are hard to define. This paper considers "big" dreams under several more easily definable subcategories: memorable dreams; important dreams (labeled by dreamer); significant dreams; and impactful dreams. Past studies are reviewed, and five new preliminary studies are presented showing that a powerful Central Image (CI) distinguishes "big" dreams in all subcategories. 1) Dreams labeled "important" by the dreamer have higher CI intensity than dreams labeled "unimportant." 2) Dreams labeled "especially significant" have especially high CI intensity. 3) Impactful dreams (leading to a new discovery) have a very high CI intensity. 4) The dreams of people who score very "thin" on the Boundary Questionnaire (BQ)--sometimes called "dream-people"--have higher CI intensity than the dreams of people who score "thick." 5) In a separate, larger group, there is a significant positive correlation between CI intensity and "thinness." It appears that CI intensity is an important measure of the "bigness" of dreams. The present results are consistent with the Contemporary Theory of Dreaming which states that dreams involve making connections guided by emotion, that the Ci of the dream pictures the emotion, and that CI intensity measures the power of the underlying emotion. "Big" dreams are dreams with great emotional power and have powerful Central Images. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Small bending,big curvature

<正>The classical "Cholodny-Went theory" predicted that directional stimuli trigger the redistribution of auxin, which governs the differential growth of plant organs through potent effects on cell expansion, thereby establishing an"auxin-then-growth" paradigm; this theory has been validated for both gravitropism and phototropism in plants(reviewed in Muthert et al., 2020).     

Non-mammalian "big" neurophysins--complete amino acid sequence of a two-domain MSEL-neurophysin from goose

Vasotocin-associated neurophysin (MSEL-neurophysin) has been purified from goose neurohypophysis through molecular sieving and high-pressure reverse-phase liquid chromatography (HPLC). The protein has a molecular mass (measured by SDS-polyacrylamide gel electrophoresis) of 17 kDa in contrast to 10 kDa found for the mammalian MSEL-neurophysins. Complete amino acid sequence (131 residues) has been determined mainly through tryptic or staphylococcal proteinase peptides derived from carboxyamidomethylated neurophysin, isolated by HPLC and microsequenced. N- and C-terminal sequences have been established by Edman degradation or action of carboxypeptidase Y, respectively, applied on the native protein. Goose MSEL-neurophysin is homologous to the two-domain "big" MSEL-neurophysin previously identified in the frog. It appears that in non-mammalian tetrapods, namely birds and amphibians, the proteolytic processing of the pro-vasotocin involves only one cleavage, releasing the hormone moiety and a "big" neurophysin with two domains homologous to mammalian MSEL-neurophysin and copeptin, respectively. Comparison of the avian protein with its mammalian and amphibian counterparts reveals that the first half of the polypeptide chain is evolutionarily much less variable than the second and that the goose protein resembles the frog protein much more than the mammalian one.     

Demonstration of "big" CRF (corticotrophin-releasing factor) in bovine hypophyseal stalk.

0.1 N HCl extracts of bovine hypophyseal stalk were fractionated with Sephadex G columns using 0.2 N acetic acid as an eluant. CRF activity of each fraction was assayed with an in vitro system employing cultured rat adenohypophyseal cells. There were 2 discrete CRF peaks with fractionation on G-100, one (Peak A) corresponding to the void volume (MW>150,000). The other (Peak B) was more retarded and eluted slightly in front of immunoreactive ACTH. CRF activity in Peak A was labile during prolonged freezing at low pH. The CRF dose-response slopes for peaks A and B were parallel and were much steeper than that for bovine cerebral cortex extract. Peak A CRF may be a precursor or carrier-bound form of Peak B CRF.     

alpha-Neo-endorphin : a "big" Leu-enkephalin with potent opiate activity from porcine hypothalami.

α-Neo-endorphin, a new morphinomimetic peptide was isolated in a yield of 50 μg from the extracts of 30,000 pig hypothalami. Its partial structure was determined by dansyl-Edman method in a nano mole scale as: Tyr-Gly-Gly-Phe-Leu-Arg-Lys-Arg-(Pro,Gly,Tyr₂,Lys₂,Arg). On the basis of our structural data, it is concluded that α-neo-endorphin is a “big” Leu-enkephalin, which has never been discovered and its structure shows no relationship with β-lipotropin. The occurence of α-neo-endorphin in brain might suggest the possible existence of a separate precursor to Leu-enkephalin distinct from that to Met-enkephalin and the other known endorphins.     

Studies on the tissue distribution and stability of "big" CRF (corticotropin-releasing factor).

Extracts of various bovine or rat neural tissues made with 0.1 N HCl, 2N acetic acid or distilled water were fractionated on Sephadex G-100 column with 0.2 N acetic acid as the eluant. A distinct peak of “big” CRF which elutes in the void volume of Sephadex G-100 was observed only with hypothalamic median eminence and hypophyseal stalk. Human serum and extracts of cerebral cortex, neurohypophysis and an ACTH-producing lung tumor, had CRF activity which eluted from Sephadex G-100 with diffuse patterns without a distinct peak. “Big” CRF is stable during storage at ?20 C in water or at 4 C in acid, but progressively disappeared when stored at ?20 C in acid.     

Climate change,collections and the classroom: using big data to tackle big problems

Preparing students to explore, understand, and resolve societal challenges such as global climate change is an important task for evolutionary and ecological biologists that will require novel and innovative pedagogical approaches. Recent calls to reform undergraduate science education emphasize the importance of engaging students in inquiry-driven, active, and authentic learning experiences. We believe that the vast digital resources (i.e., “big data”) associated with natural history collections provide invaluable but underutilized opportunities to create such experiences for undergraduates in biology. Here, we describe an online, open-access educational module that we have developed that harnesses the power of collections-based information to introduce students to multiple conceptual and analytical elements of climate change, evolutionary, and ecological biology research. The module builds upon natural history specimens and data collected over the span of nearly a century in Yosemite National Park, California, to guide students through a series of exercises aimed at testing hypotheses regarding observed differences in response to climate change by two closely related and partially co-occurring species of chipmunks. The content of the module can readily be modified to meet the pedagogical goals and instructional levels of different courses while the analytical strategies outlined can be adapted to address a wide array of questions in evolutionary and ecological biology. In sum, we believe that specimen-based natural history data represent a powerful platform for reforming undergraduate instruction in biology. Because these efforts will result in citizens who are better prepared to understand complex biological relationships, the benefits of this approach to undergraduate education will have widespread benefits to society.