Mesophotic coral ecosystems in the Hawaiian Archipelago

Efforts to map coral reef ecosystems in the Hawaiian Archipelago using optical imagery have revealed the presence of numerous scleractinian, zoothanthellate coral reefs at depths of 30–130+ m, most of which were previously undiscovered. Such coral reefs and their associated communities have been recently defined as mesophotic coral ecosystems (MCEs). Several types of MCEs are found in Hawai‘i, each of which dominates a different depth range and is characterized by a unique pattern of coral community structure and colony morphology. Although MCEs are documented near both ends of the archipelago and on many of the islands in between, the maximum depth and prevalence of MCEs in Hawai‘i were found to decline with increasing latitude. The Main Hawaiian Islands (MHI) had significantly deeper and greater percentages of scleractinian coral, and peaks in cover of both scleractinian corals and macroalgae occurred within depth bins 20 m deeper than in the Northwestern Hawaiian Islands (NWHI). Across the archipelago, as depth increased the combined percentage of living cover of mega benthic taxa declined sharply with increasing depth below 70 m, despite the widespread availability of hard substrate.     

Lignin degradation by microorganisms: A review

Lignin is an abundant plant-based biopolymer that has found applications in a variety of industries from construction to bioethanol production. This recalcitrant branched polymer is naturally degraded by many different species of microorganisms, including fungi and bacteria. These microbial lignin degradation mechanisms provide a host of possibilities to overcome the challenges of using harmful chemicals to degrade lignin biowaste in many industries. The classes and mechanisms of different microbial lignin degradation options available in nature form the primary focus of the present review. This review first discusses the chemical building blocks of lignin and the industrial sources and applications of this multifaceted polymer. The review further places emphasis on the degradation of lignin by natural means, discussing in detail the lignin degradation activities of various fungal and bacterial species. The lignin-degrading enzymes produced by various microbial species, specifically white-rot fungi, brown-rot fungi, and bacteria, are described. In the end, possible directions for future lignin biodegradation applications and research investigations have been provided.     

Optimization of procedures for separation of motile and nonmotile bull and rabbit spermatozoa with bovine serum albumin gradients

The effect of equipment design, separatory media, and time and temperature of separation were studied. Discontinuous 4%/10% bovine serum albumin (BSA) gradients were used to isolate highly motile spermatozoa in rabbit and bull semen. For all conditions tested, motility of spermatozoa collected from the 4% BSA gradient layer (top) was less than or equal to the motility of the unseparated controls. Fractions collected from the 10% BSA gradient layer contained highly motile spermatozoa. In experiment 1, washed bull spermatozoa were diluted with phosphate-buffered saline (PBS) containing 2% BSA or 4% BSA before being fractionated on BSA columns contained in test tubes. Inclusion of BSA in PBS tended to reduce loss of motility during washing, but the proportion of sperm recovered was highest in PBS. In experiment 2, motility and recovery of buck spermatozoa collected from the 10% BSA gradient region tended to be higher when fractionation temperature was 30°C as compared to 35°C, and motility was significantly higher when incubation time was 30 min as compared to 1 hr. The proportion of sperm recovered was unaffected by incubation time. In experiments 1 and 2, 41 of 48 separations resulted in at least one fraction containing spermatozoa with motility greater than or equal to 90%. In the third experiment, the surface area on which bull and buck spermatozoa were layered was increased by forming the 4%/10% BSA gradients in conical supports. Separation of sperm on conically shaped columns was not as effective as on cylinders. The use of cylinders to support the BSA gradients and a separation time of 30 min at 30°C is recommended.     

Immunochemical identity of peroxisomal enoyl-CoA hydratase with the peroxisome-proliferation -associated 80,000 mol wt polypeptide in rat liver

Peroxisome proliferators, which induce proliferation of hepatic peroxisomes, have been shown previously to cause a marked increase in an 80,000 mol wt polypeptide predominantly in the light mitochondrial and microsomal fractions of liver of rodents. We now present evidence to show that this hepatic peroxisome-proliferation-associated polypeptide, referred to as polypeptide PPA-80, is immunochemically identical with the multifunctional peroxisome protein displaying heat-labile enoyl-CoA hydratase activity. This conclusion is based on the following observations: (a) the purified polypeptide PPA-80 and the heat- labile enoyl-CoA hydratase from livers of rats treated with the peroxisome proliferators Wy-14,643 {[4-chloro-6(2,3-xylidino)-2-pyrimidinylthio]acetic acid} exhibit identical minimum molecular weights of approximately 80,000 on SDS polyacrylamide gel electrophoresis; (b) these two proteins are immunochemically identical on the basis of ouchterlony double diffusion, immunotitration, rocket immunoelectrophoresis, and crossed immunoelectrophoresis analysis; and (c) the immunoprecipitates formed by antibodies to polypeptide PPA-80 when dissociated on a sephadex G-200 column yield enoyl-CoA hydratase activity. Whether the polypeptide PPA-80 exhibits the activity of other enzyme(s) of the peroxisomal β-oxidation system such as fatty acyl-CoA oxidase activity or displays immunochemical identity with such enzymes remains to be determined. The availability of antibodies to polypeptide PPA-80 and enoyl-CoA hydratase facilitated immunofluorescent and immunocytochemical localization of the polypeptide PPA- 80 and enoyl-CoA hydratase in the rat liver. The indirect immunofluorescent studies with these antibodies provided direct visual evidence for the marked induction of polypeptide PPA-80 and enoyl-CoA hydratase in the livers of rats treated with Wy-14,643. The present studies also provide immunocytochemical evidence for the localization of polypeptide PPA- 80 and the heat-labile enoyl-CoA hydratase in the peroxisome, but not in the mitochondria, of hepatic parenchymal cells. These studies, therefore, provide morphological evidence for the existence of fatty acyl-CoA oxidizing system in peroxisomes. An increase of polypeptide PPA-80 on SDS polyacrylamide gel electrophoretic analysis of the subcellular fractions of liver of rodents treated with lipid-lowering drugs should serve as a reliable and sensitive indicator of enhanced peroxisomal β- oxidation system.     

Canine and feline host ranges of canine parvovirus and feline panleukopenia virus: distinct host cell tropisms of each virus in vitro and in vivo.

Canine parvovirus (CPV) emerged as an apparently new virus during the mid-1970s. The origin of CPV is unknown, but a variation from feline panleukopenia virus (FPV) or another closely related parvovirus is suspected. Here we examine the in vitro and in vivo canine and feline host ranges of CPV and FPV. Examination of three canine and six feline cell lines and mitogen-stimulated canine and feline peripheral blood lymphocytes revealed that CPV replicates in both canine and feline cells, whereas FPV replicates efficiently only in feline cells. The in vivo host ranges were unexpectedly complex and distinct from the in vitro host ranges. Inoculation of dogs with FPV revealed efficient replication in the thymus and, to some degree, in the bone marrow, as shown by virus isolation, viral DNA recovery, and Southern blotting and by strand-specific in situ hybridization. FPV replication could not be demonstrated in mesenteric lymph nodes or in the small intestine, which are important target tissues in CPV infection. Although CPV replicated well in all the feline cells tested in vitro, it did not replicate in any tissue of cats after intramuscular or intravenous inoculation. These results indicate that these viruses have complex and overlapping host ranges and that distinct tissue tropisms exist in the homologous and heterologous hosts.     

Defective DNA endonuclease activities in Fanconi's anemia cells, complementation groups A and B.

Cells from patients with the inherited disorder, Fanconi's anemia (FA), were analyzed for endonucleases which recognize DNA interstrand cross-links and monoadducts produced by psoralen plus UVA irradiation. Two chromatin-associated DNA endonuclease activities, defective in their ability to incise DNA-containing adducts produced by psoralen plus UVA light, have been identified and isolated in nuclei of FA cells. In FA complementation group A (FA-A) cells, one endonuclease activity, pI 4.6, which recognizes psoralen intercalation and interstrand cross-links, has 25% of the activity of the normal human endonuclease, pI 4.6, on 8-methoxypsoralen (8-MOP) plus UVA-damaged DNA. In FA complementation group B (FA-B) cells, a second endonuclease activity, pI 7.6, which recognizes psoralen monoadducts, has 50% and 55% of the activity, respectively, of the corresponding normal endonuclease on 8-MOP or angelicin plus UVA-damaged DNA. Kinetic analysis reveals that both the FA-A endonuclease activity, pI 4.6, and the FA-B endonuclease activity, pI 7.6, have decreased affinity for psoralen plus UVA-damaged DNA. Both the normal and FA endonucleases showed approximately a 2.5-fold increase in activity on psoralen plus UVA-damaged reconstituted nucleosomal DNA compared to damaged non-nucleosomal DNA, indicating that interaction of these FA endonucleases with nucleosomal DNA is not impaired. These deficiencies in two nuclear DNA endonuclease activities from FA-A and FA-B cells correlate with decreased levels of unscheduled DNA synthesis (UDS), in response to 8-MOP or angelicin plus UVA irradiation, in these cells in culture.     

The conformation of poly-L-alanine in hexafluoroisopropanol

High-molecular-weight poly-L -alanine dissolved in hexafluoroisopropanol exhibits infrared, ultraviolet, circular dichroism, and optical rotatory dispersion spectra which are unique and unlike any other previously reported polypeptide spectra. Strong evidence that a helical conformation is present is shown by the high degree of hypochromism in the 187mμ absorption peak and by the positions of the amide infrared bands. The CD and ORD spectra are also similar to those of α-helical polypeptides, though important qualitative and qualitative differences are observed. To explain the novel spectra, which are not mixtures of the spectra of previously reported polypeptide conformations, a new α-helix-like conformation is proposed. The postulated conformation (a doubly hydrogen-bonded helix) is a distorted α-helix in which the peptide carbonyl groups point slightly out from the helix axis and are hydrogen bonded simul taneously both to the NH of the fourth peptide residue to the carboxyl terminal side (as in the classical α-helix), as well as to a solvent molecule's hydroxyl hydrogen.     

Spectroscopic studies of random chain and -helical polypeptides in hexafluoroisopropanol

The infrared, ultraviolet, circular dichroism, and optical rotatory dispersion spectra of five synthetic polypeptides dissolved in hexafluoroisopropanol are reported. This solvent is useful because it dissolves most proteins and non-ionic polypeptides and also is transparent in spectral regions critical for polypeptide conformational diagnoses. Poly-γ-morpholinylethyl-L -glutamamide has random chain type spectra in this solvent, whereas the spectra of poly-γ-methyl-L -glutamate, poly-L -methionine, poly-ε, N -Carbo-benzoxy-L -lysine, and poly-L -homoserine indicate that these four polypeptides are α-helical. Small but significant variability between the different α-helical polypeptides is seen in their circular dichroism spectra and optical rotatory dispersions. An argument is presented that these differences may be due to slight geometry differences between different α-helices.     

Fertility differences among male rabbits determined by heterospermic insemination of fluorochrome-labeled spermatozoa

Spermatozoa from different bucks were stained with different fluorochromes, mixed, and inseminated heterospermically. By altering the interval between insemination and luteinizing hormone injection, spermatozoa were allowed to reside in the female tract approximately 5, 10, or 15 h prior to ovulation. The number of functional spermatozoa, from each male of a pair used, that was transported to the site of fertilization was estimated by counting total number of differently stained spermatozoa that surrounded or fertilized each oocyte. Spermatozoa from split ejaculates within a male competed against each other equally, indicating that the staining procedure did not affect fertilization or functional spermatozoal transport rates. Three pairs of males with high initial semen quality (greater than 80% motility) differed in fertility primarily due to functional spermatozoal transport. Spermatozoal survival in the female tract and capacitation time played a role in differences in male fertility when heterospermic insemination occurred at variable times relative to ovulation. Differences in fertilization not accounted for by spermatozoal transport ratio raised the possibility that rate of egg penetration due to acrosomal enzyme differences may be important in determining male fertility. Therefore, total acrosin, hyaluronidase, and arylsulfatase activity in spermatozoa from specific bucks used in fertilization experiments were determined. Although there were trends favoring high fertility when enzyme content was higher, the difference was significant only for arylsulfatase in one buck.