Walker's Mammals of the World, 4th Edition, Ronald M. Nowak, John L. Paradiso. The Johns Hopkins University Press, Baltimore, Maryland (1983), 1xi, +1-568 (Vol. I), xxv+569-1362 (Vol. II). Price $65.00

AMPHIBIAN DECLINES: THE CONSERVATION STATUS OF UNITED STATES SPECIES. Michael Lannoo (ed.). 2005. University of California Press, Berkeley. ISBN 0-520-235924. XXI + 1094 p. $95.00 (hard cover).—During the past decade and a half, much has been discussed and published on amphibian declines. The new information obtained created a novel field of research in herpetology. The starting point of this new field was the First World Congress of Herpetology, held in Canterbury, England, in 1989, when herpetologists found that the amphibian disappearances they had witnessed individually were not merely rare, local phenomena but rather appeared to be occurring around the globe. The relevance of amphibian declines can be measured not only by the scientific production but also by the extensive coverage by the popular press. The book ‘‘Amphibian Declines: The Conservation Status of United States Species’’ summarizes the advances of this new research field, mainly in the United States. This is an extraordinary book based on the experience of an impressive team of specialists on amphibian declines and conservation, primarily focused on species from the United States. Because North American herpetologists have accumulated detailed data on native amphibians over many years, this book is very thorough. The book is divided into two parts; part one is a collection of 52 essays on conservation written mainly by researchers with extensive experience in amphibian conservation. This first part is divided into an Introduction and chapters titled Declines, Causes, Conservation, Surveys and Monitoring, Education, and Perspective. Part two corresponds to the species accounts for Anura and Caudata. An amazing total of 215 contributors participated in the two parts of the book, producing more than a thousand pages of rich information on amphibian declines and conservation in United States. The essays vary in detail and breadth of coverage, and there is some overlap among some of them, but this is to be expected in a book written by so many scientists. In the Introduction there are five essays that provide a historical perspective on the conservation of amphibians. In the Declines chapter five essays give a historical perspective as well, but there is also specific information on the decline of cricket frogs (Acris crepitans) and a data-rich essay on the decline of the salamanders of the genus Plethodon. Together the essays address all of the relevant topics of conservation and decline in amphibians. For example, the first essay by Tim Halliday addresses the main reasons for amphibian declines, summarizing recent progress that is improving our understanding on the causal factors promoting it. He indicates habitat destruction, climate change, pollution, increased UV-B radiation, and disease as the main factors, but also calls attention to the synergistic action among some of these causes. The necessity of a more ample comprehension of the conservation status of other groups of organisms is also highlighted, given that declines may also be severe in other taxa, such as bivalves. The lack of data on distribution, population structure, and habitat of amphibians makes the task of protection more difficult. In the second essay, Martha L. Crump discusses why some species are in decline while others are not. She compares studies in different parts of the world and concludes that the patterns associated with declines in one assemblage are not necessarily repeated in other assemblages. She did not find a clear pattern of differences (in phylogeny, distribution, habitat, activity, diet, body size, skin characteristics, and life history traits) between declining and non-declining species. She concludes that some species are less able to cope with anthropogenic environmental changes. In Causes, 12 essays adequately cover the main causes that have been proposed or demonstrated to be involved in amphibian declines. Global warming, UV radiation, chemical pollution, parasites and malformations, habitat destruction or alteration, and commercial trade of amphibians are among the treated topics. However, in this chapter some essays are not related to the causes of decline per se, such as the essay on the Lucké renal adenocarcinoma in Northern Leopard Frogs (Lithobates pipiens). In this case there is no evidence that the carcinoma is a factor in frog population decline. In Conservation, 18 essays treat different aspects of amphibian conservation. There are essays on the conservation of specific taxa, such as one on the endangered Houston Toad (Anaxyrus houstonensis) that includes information on the major causes of decline and the politics that play an important role in conservation. The essay on fluctuations in the size of tiger salamander populations provides useful information for understanding the related natural and anthropogenic factors that affect this amphibian. The essay on the Texas spring and cave salamanders (Eurycea) shows that most species have restricted distributions and are threatened by human activities. The essay on the Southwestern desert bufonids indicates that, although these toads escaped the declines experienced by many anurans, some species are being eliminated from some areas as a result of habitat alteration. Two essays raise questions on taxonomic and systematic problems and the conservation status of the amphibians. They call attention to the necessity of clear and workable systems of classification to describe biodiversity, the importance of phylogenetic taxonomies, and the importance of conservation systematics in management and politics. The essay by Karen R. Lips and Maureen A. Donnelly is an exception in the book in that it aims to describe the nature, extent, and possible causes of amphibian declines in the tropics and not in United States. The limitation of this essay is the lack of data on tropical amphibian, which is not the authors’ fault (see below). Other essays in this chapter are on amphibian decline and management, landscape ecology, ecotoxicology, importance of museum collections in amphibian conservation, reserve network, population manipulations of imperiled species, exotic invading species of fish and amphibians and their impacts on the natural systems, and the importance of natural history in the conservation of amphibians. In the Surveys and Monitoring chapter, nine essays cover general and specific aspects, including methodological proposals. Some essays treat the distribution, decline, and monitoring of amphibians from specific places in the United States or from a general program, the North American

Amphibian Declines: The Conservation Status of United States Species

Non-invasive measurement of glucocorticoids: Advances and problems

Porcine in vitro production (IVP) systems, including in vitro maturation (IVM) and in vitro fertilization (IVF) of oocytes and their subsequent in vitro culture (IVC), have been modified by many researchers, but are still at a low level because of a low developmental rate of embryos to the blastocyst stage and their poor qualities. Our objectives were to establish reliable IVP procedures for porcine blastocysts and to examine the ability of the blastocysts to develop to term after transfer to recipients. Porcine cumulus-oocyte complexes were matured in vitro under 5% O(2) or 20% O(2), fertilized in vitro under 5% O(2), and subsequently cultured under 5% O(2) in 1) IVC medium supplemented with glucose (IVC-Glu) from Day 0 (the day of IVF) to Day 6; 2) IVC-Glu from Days 0 to 2, then IVC medium supplemented with pyruvate and lactate (IVC-PyrLac) from Days 2 to 6; 3) IVC-PyrLac from Days 0 to 2, then IVC-Glu from Days 2 to 6; and 4) IVC-PyrLac from Days 0 to 6. There were no significant differences in blastocyst formation rates on Day 6 between the 5% O(2) and 20% O(2) conditions (19.9% and 14.0%, respectively). However, the quality of blastocysts, as evaluated by the total cell number, was better after IVM under 5% O(2) than under 20% O(2) (mean cell number, 43.5 and 37.8, respectively). When IVP embryos were cultured in IVC-PyrLac from Days 0 to 2 and subsequently in IVC-Glu from Days 2 to 6, the rate of blastocyst formation (25.3%) and cell number (48.7) were higher than the rates (5.8% to 18.1%) and numbers (35.4 to 37.1) with the IVC-Glu then IVC-Glu, the IVC-Glu then IVC-PyrLac, and the IVC-PyrLac then IVC-PyrLac regimens, respectively. We then prepared conditioned medium (CM) from culture of porcine oviductal epithelial cells for 2 days in IVC-PyrLac and evaluated its effect on development to the blastocyst stage. Cultivation in CM for the first 2 days, followed by IVC-Glu for a further 4 days, had a significantly greater effect in increasing the number of cells in the blastocyst (58.3) than did in IVC-PyrLac (48.4). Finally, we evaluated the ability of blastocysts, generated by IVM under 5% O(2) and IVC in CM, to develop to term. When Day 5 expanding blastocysts (mean cell number, 49.7) were transferred to an estrus-synchronized recipient (50 blastocysts per recipient), the recipient remained pregnant and farrowed eight normal piglets. Furthermore, when Day 6 expanded blastocysts (mean cell number, 80.2) were transferred to two estrus-synchronized recipients, both gilts remained pregnant and farrowed a total of 11 piglets. These results suggest that an excellent piglet production system can be established by using this modified IVP system, which produces high-quality porcine blastocysts. This system has advantages for the generation of cloned and transgenic pigs.

https://bioone.org/journals/biology-of-reproduction/volume-66/issue-4/biolreprod66.4.1033/Successful-Piglet-Production-after-Transfer-of-Blastocysts-Produced-by-a/10.1095/biolreprod66.4.1033.pdf

Successful Piglet Production after Transfer of Blastocysts Produced by a Modified In Vitro System

During late follicular growth, oestrus, fertilization and early embryonic development, the oviduct, under specific hormonal control, produces fluid and contributes secretory macromolecules that optimize the microenvironment for gamete maturation and transport, fertilization and early cleavage-stage embryonic development. This review describes the state of knowledge concerning the physiological and biochemical characterization of the major oviduct secreted protein, the oviduct-specific, oestrogen-dependent glycoprotein. The identification, localization within the oviduct, binding and association with oocytes, embryos and spermatozoa, hormonal control of gene expression, cloning, gene organization, protein sequences and post-translational modifications of oviduct-specific, oestrogen-dependent glycoprotein are discussed. Identification of biological functions for this glycoprotein, its interactions with spermatozoa, oocytes and embryos and its potential as a paracrine regulator of fertilization and development are also discussed.

/pdf/characterization-and-biological-roles-of-oviduct-specific-3noycjxodc.pdf

Characterization and biological roles of oviduct-specific, oestrogen-dependent glycoprotein

During late follicular development and estrus, the mammalian oviduct undergoes specific physiological and biochemical modifications which contribute to an optimization of the microenvironment for fertilization and early cleavage-stage embryonic development. These changes appear to be hormonally regulated by ovarian steroids, most importantly, estrogen. The hundreds of macromolecules found within the oviductal lumen are contributed by selective serum transudation and active biosynthesis and secretion from nonciliated epithelial cells. Recent studies have indicated temporal and regional (infundibulum, ampulla and isthmus) differences in steady-state levels of specific mRNAs and in de novo protein synthesis and secretion by the oviduct. One protein synthesized de novo, the estrogen-dependent oviductal secretory glycoprotein (OSP), has been shown to be unique to the oviduct and is conserved across a number of mammalian species. This protein associates with the zona pellucida, perivitelline space and vitelline or blastomere membrane of ovulated eggs and preimplantation embryos. OSPs have been shown to enhance sperm binding and penetration in oocytes and may regulate development in early preimplantation embryos. Other regulatory molecules, protease inhibitors, growth factors, cytokines, binding proteins, enzymes and immunoglobulins have been identified in the oviductal microenvironment. The identification and potential roles for oviduct-secreted proteins will be reviewed and discussed. Current research focuses on continued identification and characterization of specific oviductal proteins and a determination of the molecular basis of their interactions with the oocyte, sperm or embryo.

Secreted proteins of the oviduct

This study evaluated the effects of porcine oviduct-specific glycoprotein (pOSP) on in vitro fertilization (IVF), polyspermy, and development to blastocyst. Experiment 1 evaluated the effects of various concentrations (0‐100 mg/ml) of purified pOSP on fertilization parameters, including penetration, polyspermy, male pronuclear formation, and mean number of sperm penetrated per oocyte. Experiment 2 examined the ability of an antipOSP immunoglobulin G to inhibit the observed effects of pOSP on fertilization parameters. Experiments 3 and 4 examined various concentrations of pOSP (0‐100 mg/ml) on zona pellucida solubility and sperm binding, respectively. Lastly, experiment 5 assessed the effects of various concentrations of pOSP (0‐100 mg/ml) on the in vitro embryo cleavage rate and development to blastocyst. Pig oocytes matured and fertilized in vitro were used for all experiments. An effect of treatment (P , 0.05) was detected for pOSP on penetration, polyspermy, and mean number of sperm per oocyte. Concentrations for pOSP of 0‐50 mg/ ml had no effect on sperm penetration rates; however, compared with the control, 100 mg/ml significantly decreased the penetration rate (74% vs. 41%). Addition of 10‐100 mg/ml significantly reduced the polyspermy rate compared with the control (61% vs. 24‐29%). The decrease in polyspermy achieved by addition of pOSP during preincubation and IVF was blocked with a specific antibody to pOSP. No effect of treatment was observed on zona digestion time relative to the control; however, the number of sperm bound to the zona pellucida was significantly decreased by treatment (P , 0.05). Compared with the control, all concentrations of pOSP examined reduced the number of sperm bound per oocyte (45 vs. 19‐34). A treatment effect (P , 0.05) was observed for pOSP on embryo development to blastocyst but not on cleavage rates. Addition of pOSP during preincubation and fertilization significantly increased postcleavage development to blastocyst, but a synergistic stimulation on development was not detected when pOSP was included during in vitro culture. These results indicate that exposure to pOSP before and during fertilization reduces the incidence of polyspermy in pig oocytes, reduces the number of bound sperm, and increases postcleavage development to blastocyst. fertilization, oviduct

https://bioone.org/journals/biology-of-reproduction/volume-63/issue-1/biolreprod63.1.242/Effects-of-the-Porcine-Oviduct-Specific-Glycoprotein-on-Fertilization-Polyspermy/10.1095/biolreprod63.1.242.pdf

Effects of the Porcine Oviduct-Specific Glycoprotein on Fertilization, Polyspermy, and Embryonic Development In Vitro

Insulin-like growth factor I (IGF-I) has been identified in human seminal plasma. This study was conducted to determine whether IGF-I is present in bovine seminal plasma, whether sperm cells express the IGF-I receptor (IGF-IR), and whether IGF-I affects sperm motility. Semen samples were collected from bulls by electroejaculation and maintained at 378C, and motility of sperm was assessed. After centrifugation to separate sperm cells from seminal plasma, the seminal plasma was submitted to a validated heterologous RIA for IGF-I. Significant concentrations of IGF-I (116.29 6 40.83 ng/ml expressed as mean 6 SD) were measured in bovine seminal plasma. Sperm cells were washed with buffer and subjected to either radioreceptor assay (RRA) or immunocytochemistry (IC). RRA revealed a single high affinity for the IGF-IR with a Kd of 0.83 nM as determined by the computer program LIGAND. IC, using three monoclonal antibodies, localized the IGF-IR to the acrosomal region of the sperm. Computer-assisted sperm-motion analysis was used to determine the effects of IGF-I and IGF-II on bovine sperm motility parameters. Both IGF-I and IGF-II increased sperm motility and straight-line velocity (p , 0.05) relative to the control. The presence of IGF-IR on sperm, the presence of IGF-I in semen, and the ability of IGF-I to stimulate sperm motility provide evidence that the IGF system may be involved in the fertilization process in the bovine species.

Identification of Insulin-Like Growth Factor I in Bovine Seminal Plasma and Its Receptor on Spermatozoa: Influence on Sperm Motility

Artificial fertilization for amphibian conservation: current knowledge and future considerations.

As amphibian populations continue to decline, both government and non-government organisations are establishing captive assurance colonies to secure populations deemed at risk of extinction if left in the wild. For the most part, little is known about the nutritional ecology, reproductive biology or husbandry needs of the animals placed into captive breeding programs. Because of this lack of knowledge, conservation biologists are currently facing the difficult task of maintaining and reproducing these species. Academic and zoo scientists are beginning to examine different technologies for maintaining the genetic diversity of founder populations brought out of the wild before the animals become extinct from rapidly spreading epizootic diseases. One such technology is genetic resource banking and applied reproductive technologies for species that are difficult to reproduce reliably in captivity. Significant advances have been made in the last decade for amphibian assisted reproduction including the use of exogenous hormones for induction of spermiation and ovulation, in vitro fertilisation, short-term cold storage of gametes and long-term cryopreservation of spermatozoa. These scientific breakthroughs for a select few species will no doubt serve as models for future assisted breeding protocols and the increasing number of amphibians requiring conservation intervention. However, the development of specialised assisted breeding protocols that can be applied to many different families of amphibians will likely require species-specific modifications considering their wide range of reproductive modes. The purpose of this review is to summarise the current state of knowledge in the area of assisted reproduction technologies and gene banking for the conservation of amphibians.

Andrew J. Kouba

Papers

Secreted proteins of the oviduct

Effects of the Porcine Oviduct-Specific Glycoprotein on Fertilization, Polyspermy, and Embryonic Development In Vitro

Identification of Insulin-Like Growth Factor I in Bovine Seminal Plasma and Its Receptor on Spermatozoa: Influence on Sperm Motility

Artificial fertilization for amphibian conservation: current knowledge and future considerations.

Applied reproductive technologies and genetic resource banking for amphibian conservation