26
|
Butchart SHM, Scharlemann JPW, Evans MI, Quader S, Aricò S, Arinaitwe J, Balman M, Bennun LA, Bertzky B, Besançon C, Boucher TM, Brooks TM, Burfield IJ, Burgess ND, Chan S, Clay RP, Crosby MJ, Davidson NC, De Silva N, Devenish C, Dutson GCL, Fernández DFDZ, Fishpool LDC, Fitzgerald C, Foster M, Heath MF, Hockings M, Hoffmann M, Knox D, Larsen FW, Lamoreux JF, Loucks C, May I, Millett J, Molloy D, Morling P, Parr M, Ricketts TH, Seddon N, Skolnik B, Stuart SN, Upgren A, Woodley S. Protecting important sites for biodiversity contributes to meeting global conservation targets. PLoS One 2012; 7:e32529. [PMID: 22457717 PMCID: PMC3310057 DOI: 10.1371/journal.pone.0032529] [Citation(s) in RCA: 198] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 01/30/2012] [Indexed: 11/19/2022] Open
Abstract
Protected areas (PAs) are a cornerstone of conservation efforts and now cover nearly 13% of the world's land surface, with the world's governments committed to expand this to 17%. However, as biodiversity continues to decline, the effectiveness of PAs in reducing the extinction risk of species remains largely untested. We analyzed PA coverage and trends in species' extinction risk at globally significant sites for conserving birds (10,993 Important Bird Areas, IBAs) and highly threatened vertebrates and conifers (588 Alliance for Zero Extinction sites, AZEs) (referred to collectively hereafter as ‘important sites’). Species occurring in important sites with greater PA coverage experienced smaller increases in extinction risk over recent decades: the increase was half as large for bird species with>50% of the IBAs at which they occur completely covered by PAs, and a third lower for birds, mammals and amphibians restricted to protected AZEs (compared with unprotected or partially protected sites). Globally, half of the important sites for biodiversity conservation remain unprotected (49% of IBAs, 51% of AZEs). While PA coverage of important sites has increased over time, the proportion of PA area covering important sites, as opposed to less important land, has declined (by 0.45–1.14% annually since 1950 for IBAs and 0.79–1.49% annually for AZEs). Thus, while appropriately located PAs may slow the rate at which species are driven towards extinction, recent PA network expansion has under-represented important sites. We conclude that better targeted expansion of PA networks would help to improve biodiversity trends.
Collapse
|
27
|
Dotson-Blake KP, Knox D, Zusman ME. Exploring Social Sexual Scripts Related to Oral Sex: A Profile of College Student Perceptions. ACTA ACUST UNITED AC 2012. [DOI: 10.15241/kpd.2.1.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
28
|
Burke SC, Wallen M, Vail-Smith K, Knox D. Using technology to control intimate partners: An exploratory study of college undergraduates. COMPUTERS IN HUMAN BEHAVIOR 2011. [DOI: 10.1016/j.chb.2010.12.010] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
29
|
Knox D, Murray G, Millar M, Hamilton D, Connor M, Ferdinand RD, Jones GA. Subcutaneous anthrax in three intravenous drug users: a new clinical diagnosis. ACTA ACUST UNITED AC 2011; 93:414-7. [PMID: 21357967 DOI: 10.1302/0301-620x.93b3.25976] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Anthrax is extremely rare in the western world but is endemic to areas of south and central Asia. In early 2010 an outbreak was identified in heroin-injecting intravenous drug users in the United Kingdom and Europe. Afghanistan is currently the principal source of heroin which reaches the United Kingdom. When anthrax occurs, cutaneous disease accounts for over 95% of cases. At least 47 cases with 13 deaths have been confirmed so far. We present three cases presenting during this time with marked swelling, one resulting in compartment syndrome but all with an absence of the expected cutaneous appearances. We suggest that rather than cutaneous anthrax, these patients represent a new subcutaneous presentation of anthrax.
Collapse
|
30
|
Fridjonsson O, Olafsson K, Tompsett S, Bjornsdottir S, Consuegra S, Knox D, de Leaniz CG, Magnusdottir S, Olafsdottir G, Verspoor E, Hjorleifsdottir S. Detection and mapping of mtDNA SNPs in Atlantic salmon using high throughput DNA sequencing. BMC Genomics 2011; 12:179. [PMID: 21473771 PMCID: PMC3079667 DOI: 10.1186/1471-2164-12-179] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 04/07/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Approximately half of the mitochondrial genome inherent within 546 individual Atlantic salmon (Salmo salar) derived from across the species' North Atlantic range, was selectively amplified with a novel combination of standard PCR and pyro-sequencing in a single run using 454 Titanium FLX technology (Roche, 454 Life Sciences). A unique combination of barcoded primers and a partitioned sequencing plate was employed to designate each sequence read to its original sample. The sequence reads were aligned according to the S. salar mitochondrial reference sequence (NC_001960.1), with the objective of identifying single nucleotide polymorphisms (SNPs). They were validated if they met with the following three stringent criteria: (i) sequence reads were produced from both DNA strands; (ii) SNPs were confirmed in a minimum of 90% of replicate sequence reads; and (iii) SNPs occurred in more than one individual. RESULTS Pyrosequencing generated a total of 179,826,884 bp of data, and 10,765 of the total 10,920 S. salar sequences (98.6%) were assigned back to their original samples. The approach taken resulted in a total of 216 SNPs and 2 indels, which were validated and mapped onto the S. salar mitochondrial genome, including 107 SNPs and one indel not previously reported. An average of 27.3 sequence reads with a standard deviation of 11.7 supported each SNP per individual. CONCLUSION The study generated a mitochondrial SNP panel from a large sample group across a broad geographical area, reducing the potential for ascertainment bias, which has hampered previous studies. The SNPs identified here validate those identified in previous studies, and also contribute additional potentially informative loci for the future study of phylogeography and evolution in the Atlantic salmon. The overall success experienced with this novel application of HT sequencing of targeted regions suggests that the same approach could be successfully applied for SNP mining in other species.
Collapse
|
31
|
Knox D. Proteases in blood-feeding nematodes and their potential as vaccine candidates. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 712:155-76. [PMID: 21660664 DOI: 10.1007/978-1-4419-8414-2_10] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Parasitic nematodes express and secrete a variety of proteases which they use for many purposes including the penetration of host tissues, digestion of host protein for nutrients, evasion of host immune responses and for internal processes such as tissue catabolism and apoptosis. For these broad reasons they have been examined as possible parasite control targets. Blood-feeding nematodes such as the barber-pole worm Haemonchus contortus that infect sheep and goats and the hookworms, Ancylostoma spp. and Necator americanus, affecting man, use an array of endo- and exopeptidases to digest the blood meal. Haemoglobin digestion occurs by an ordered and partly conserved proteolytic cascade. These proteases are accessible to host immune responses which can block enzyme function and lead to parasite expulsion and/or death. Thus they are receiving attention as components of vaccines against several parasitic nematodes of social and economic importance.
Collapse
|
32
|
Vail-Smith K, Whetstone LM, Knox D. The illusion of safety in "monogamous" undergraduate relationships. Am J Health Behav 2010; 34:12-20. [PMID: 19663747 DOI: 10.5993/ajhb.34.1.2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVES To determine the prevalence of sexual infidelity and disclosure among undergraduates and to identify the characteristics of those engaging in infidelity. METHODS Analysis of responses from an online survey of 1341 undergraduate. RESULTS Approximately 27% of males and 20% of females reported having oral, vaginal, or anal sex outside a partner-perceived monogamous relationship. Men over the age of 20, binge drinkers, fraternity members, male NCAA athletes, or the nonreligious were most likely to engage in these behaviors. CONCLUSIONS Implement educational strategies to encourage undergraduates in committed relationships to reconsider their STI risk and to protect themselves via condom usage.
Collapse
|
33
|
Downing MR, Knox D, Gibson P, Reid DM, Potter A, Ashcroft GP. Impact of trochanteric heterotopic ossification on measurement of femoral bone density following cemented total hip replacement. J Orthop Res 2008; 26:1334-9. [PMID: 18404740 DOI: 10.1002/jor.20636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
During a study of bone mineral density changes around cemented femoral implants, we recognized heterotopic ossification occurring regularly in a position anterior to the greater trochanter and proximal femur. The aim of this study was to describe the incidence, distribution, and effect of this ossification on periprosthetic DXA scans following primary cemented total hip replacement. One hundred eleven patients underwent postoperative DXA examinations measuring changes in bone mineral density with heterotopic ossification identified and localized on standard radiographs with confirmation using DXA subtraction imaging. Male gender and age within the male group were significantly associated with occurrence of heterotopic ossification (p = 0.003 and 0.046, respectively). Femoral stem type, weight, and body mass index had no significant effect (p = 0.525, 0.372, and 0.243, respectively). Examining the Gruen zones in all patients suggested a median (plus interquartile range) zone 1 density drop of 4% (-12% to +7%). When separated and analyzed for the effect of heterotopic ossification, the 45 patients with heterotopic ossification showed a 2-year density gain of +6% (-5% to +15%), whereas those without heterotopic ossification showed a loss of 8% (-14% to 0%), a significant difference (p < 0.001). Zone 2 also showed a significant difference (p = 0.048). We therefore recommend that affected zones should be identified and excluded from analysis at all time points. Without this precaution, researchers risk underestimating periprosthetic bone loss in their studies and reporting misleading conclusions.
Collapse
|
34
|
Andreone F, Carpenter AI, Cox N, du Preez L, Freeman K, Furrer S, Garcia G, Glaw F, Glos J, Knox D, Köhler J, Mendelson JR, Mercurio V, Mittermeier RA, Moore RD, Rabibisoa NHC, Randriamahazo H, Randrianasolo H, Raminosoa NR, Ramilijaona OR, Raxworthy CJ, Vallan D, Vences M, Vieites DR, Weldon C. The challenge of conserving amphibian megadiversity in Madagascar. PLoS Biol 2008; 6:e118. [PMID: 18462021 PMCID: PMC2365978 DOI: 10.1371/journal.pbio.0060118] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Highly diverse and so far apparently untouched by emergent diseases, Malagasy frogs nevertheless are threatened by ongoing habitat destruction, making pro-active conservation actions especially important for preserving this unique, pre-decline, amphibian fauna.
Collapse
|
35
|
|
36
|
|
37
|
Geldhof P, Visser A, Clark D, Saunders G, Britton C, Gilleard J, Berriman M, Knox D. RNA interference in parasitic helminths: current situation, potential pitfalls and future prospects. Parasitology 2007; 134:609-19. [PMID: 17201997 DOI: 10.1017/s0031182006002071] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYRNA interference (RNAi) has become an invaluable tool for the functional analysis of genes in a wide variety of organisms including the free-living nematode Caenorhabditis elegans. Recently, attempts have been made to apply this technology to parasitic helminths of animals and plants with variable success. Gene knockdown has been reported for Schistosoma mansoni by soaking or electroporating different life-stages in dsRNA. Similar approaches have been tested on parasitic nematodes which clearly showed that, under certain conditions, it was possible to interfere with gene expression. However, despite these successes, the current utility of this technology in parasite research is questionable. First, problems have arisen with the specificity of RNAi. Treatment of the parasites with dsRNA resulted, in many cases, in non-specific effects. Second, the current RNAi methods have a limited efficiency and effects are sometimes difficult to reproduce. This was especially the case in strongylid parasites where only a small number of genes were susceptible to RNAi-mediated gene knockdown. The future application of RNAi in parasite functional genomics will greatly depend on how we can overcome these difficulties. Optimization of the dsRNA delivery methods and in vitro culture conditions will be the major challenges.
Collapse
|
38
|
Ricketts TH, Dinerstein E, Boucher T, Brooks TM, Butchart SHM, Hoffmann M, Lamoreux JF, Morrison J, Parr M, Pilgrim JD, Rodrigues ASL, Sechrest W, Wallace GE, Berlin K, Bielby J, Burgess ND, Church DR, Cox N, Knox D, Loucks C, Luck GW, Master LL, Moore R, Naidoo R, Ridgely R, Schatz GE, Shire G, Strand H, Wettengel W, Wikramanayake E. Pinpointing and preventing imminent extinctions. Proc Natl Acad Sci U S A 2005; 102:18497-501. [PMID: 16344485 PMCID: PMC1311739 DOI: 10.1073/pnas.0509060102] [Citation(s) in RCA: 208] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Indexed: 11/18/2022] Open
Abstract
Slowing rates of global biodiversity loss requires preventing species extinctions. Here we pinpoint centers of imminent extinction, where highly threatened species are confined to single sites. Within five globally assessed taxa (i.e., mammals, birds, selected reptiles, amphibians, and conifers), we find 794 such species, three times the number recorded as having gone extinct since 1500. These species occur in 595 sites, concentrated in tropical forests, on islands, and in mountainous areas. Their taxonomic and geographical distribution differs significantly from that of historical extinctions, indicating an expansion of the current extinction episode beyond sensitive species and places toward the planet's most biodiverse mainland regions. Only one-third of the sites are legally protected, and most are surrounded by intense human development. These sites represent clear opportunities for urgent conservation action to prevent species loss.
Collapse
|
39
|
Consuegra S, Verspoor E, Knox D, García de Leániz C. Asymmetric gene flow and the evolutionary maintenance of genetic diversity in small, peripheral Atlantic salmon populations. CONSERV GENET 2005. [DOI: 10.1007/s10592-005-9042-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
40
|
Morris D, Knox D, Lavoie J, Lemon J, Boreham D. Po-Poster - 28: Examination of gene expression in p53(+/−) mice exposed to low dose radiation using Affymetrix cDNA microarrays. Med Phys 2005. [DOI: 10.1118/1.2031007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
41
|
Paterson S, Piertney SB, Knox D, Gilbey J, Verspoor E. Characterization and PCR multiplexing of novel highly variable tetranucleotide Atlantic salmon (Salmo salar L.) microsatellites. ACTA ACUST UNITED AC 2004. [DOI: 10.1111/j.1471-8286.2004.00598.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
42
|
Hotez PJ, Zhan B, Bethony JM, Loukas A, Williamson A, Goud GN, Hawdon JM, Dobardzic A, Dobardzic R, Ghosh K, Bottazzi ME, Mendez S, Zook B, Wang Y, Liu S, Essiet-Gibson I, Chung-Debose S, Xiao S, Knox D, Meagher M, Inan M, Correa-Oliveira R, Vilk P, Shepherd HR, Brandt W, Russell PK. Progress in the development of a recombinant vaccine for human hookworm disease: the Human Hookworm Vaccine Initiative. Int J Parasitol 2004; 33:1245-58. [PMID: 13678639 DOI: 10.1016/s0020-7519(03)00158-9] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hookworm infection is one of the most important parasitic infections of humans, possibly outranked only by malaria as a cause of misery and suffering. An estimated 1.2 billion people are infected with hookworm in areas of rural poverty in the tropics and subtropics. Epidemiological data collected in China, Southeast Asia and Brazil indicate that, unlike other soil-transmitted helminth infections, the highest hookworm burdens typically occur in adult populations, including the elderly. Emerging data on the host cellular immune responses of chronically infected populations suggest that hookworms induce a state of host anergy and immune hyporesponsiveness. These features account for the high rates of hookworm reinfection following treatment with anthelminthic drugs and therefore, the failure of anthelminthics to control hookworm. Despite the inability of the human host to develop naturally acquired immune responses to hookworm, there is evidence for the feasibility of developing a vaccine based on the successes of immunising laboratory animals with either attenuated larval vaccines or antigens extracted from the alimentary canal of adult blood-feeding stages. The major antigens associated with each of these larval and adult hookworm vaccines have been cloned and expressed in prokaryotic and eukaryotic systems. However, only eukaryotic expression systems (e.g., yeast, baculovirus, and insect cells) produce recombinant proteins that immunologically resemble the corresponding native antigens. A challenge for vaccinologists is to formulate selected eukaryotic antigens with appropriate adjuvants in order to elicit high antibody titres. In some cases, antigen-specific IgE responses are required to mediate protection. Another challenge will be to produce anti-hookworm vaccine antigens at high yield low cost suitable for immunising large impoverished populations living in the developing nations of the tropics.
Collapse
|
43
|
Berntson GG, Shafi R, Knox D, Sarter M. Blockade of epinephrine priming of the cerebral auditory evoked response by cortical cholinergic deafferentation. Neuroscience 2003; 116:179-86. [PMID: 12535951 DOI: 10.1016/s0306-4522(02)00702-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The present study tested hypotheses derived from a neurobehavioral model of anxiety that posits an important role of the basal forebrain cholinergic system in the cortical processing of anxiety-associated stimuli and contexts. We hypothesized that visceral afferent activity induced by systemic administration of epinephrine would enhance the processing of auditory stimuli as evidenced by the cerebral auditory evoked response. We further predicted that selective lesions of the basal forebrain cortical cholinergic projection system would disrupt this processing, and would further block the effects of epinephrine. Results confirmed these hypotheses. Epinephrine was found to enhance the amplitude of the P70 component of the auditory evoked response in rats. Selective lesions of the basal forebrain corticopetal cholinergic projection, by intrabasalis infusions of 192 IgG saporin, delayed and reduced the amplitude of the P70 component, and blocked the potentiating effects of epinephrine on the auditory evoked response. The present results are consistent with the view that visceral afferent input may modulate cortical processing of sensory signals via the basal forebrain cholinergic system. These considerations emphasize the potential importance of ascending, bottom-up modulation of processing by telencephalic circuits that may impact on a wide range of behavioral functions.
Collapse
|
44
|
Geldhof P, Vercauteren I, Knox D, Demaere V, Van Zeveren A, Berx G, Vercruysse J, Claerebout E. Protein disulphide isomerase of Ostertagia ostertagi: an excretory-secretory product of L4 and adult worms? Int J Parasitol 2003; 33:129-36. [PMID: 12633650 DOI: 10.1016/s0020-7519(02)00260-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A pepstatin A-agarose column was used in an attempt to purify a previously described antibody-degrading aspartyl proteinase from excretory-secretory material from the L4 and the adult stages of the bovine abomasal nematode Ostertagia ostertagi. However, no aspartyl proteinase activity was detected in the eluted fractions (L4Pepst and AdPepst). Screening of cDNA libraries with polyclonal antibodies raised against L4Pepst and AdPepst showed that a protein disulphide isomerase (Ost-PDI2) was present in both antigen fractions. This multifunctional enzyme was detected in extracts of L3, L4 and adult parasites and, interestingly, also in excretory-secretory material of L4 and adult O. ostertagi. By immunohistochemistry, the Ost-PDI2 enzyme was localised in some parts of the hypodermis of L4 and adult worms and in the intestinal cells of all three parasitic life stages. Two-dimensional Western blot analysis indicated that Ost-PDI2 is recognised by calves during a natural O. ostertagi infection, which suggests that Ost-PDI2 could be used for immunological control of ostertagiosis.
Collapse
|
45
|
Verspoor E, O'Sullivan M, Arnold AL, Knox D, Amiro PG. Restricted matrilineal gene flow and regional differentiation among Atlantic salmon (Salmo salar L.) populations within the Bay of Fundy, eastern Canada. Heredity (Edinb) 2002; 89:465-72. [PMID: 12466990 DOI: 10.1038/sj.hdy.6800166] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2001] [Accepted: 07/16/2002] [Indexed: 11/08/2022] Open
Abstract
Matrilineal phylogenetic divergence among Atlantic salmon stocks of the Bay of Fundy in south eastern Canada is investigated. Sequence variation in two regions of the mitochondrial ND1 gene, encompassing 710 base pairs, is described for 168 salmon from 11 rivers. Mean overall haplotype and nucleotide diversity (h and pi) observed are 0.5014 and 0.00095, respectively. Nested clade analysis (NCA) and molecular analysis of variance (AMOVA) both point to highly restricted gene flow among rivers and show the haplotype distribution to be geographically structured. Variation among predefined regions of the Bay (16%) is greater than among populations within these regions (14%) The main regional differentiation occurs between rivers of the geographically isolated inner Minas Basin and those elsewhere in the Bay. Differentiation most probably reflects the pattern and nature of the historical processes associated with post-glacial colonisation of the area by salmon following the last Pleistocene glacial maximum c. 180,00 yrs BP.
Collapse
|
46
|
Consuegra S, García de Leániz C, Serdio A, González Morales M, Straus LG, Knox D, Verspoor E. Mitochondrial DNA variation in Pleistocene and modern Atlantic salmon from the Iberian glacial refugium. Mol Ecol 2002; 11:2037-48. [PMID: 12296947 DOI: 10.1046/j.1365-294x.2002.01592.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Current understanding of the postglacial colonization of Nearctic and Palearctic species relies heavily on inferences drawn from the phylogeographic analysis of contemporary generic variants. Modern postglacial populations are supposed to be representative of their Pleistocene ancestors, and their current distribution is assumed to reflect the different colonization success and dispersal patterns of refugial lineages. Yet, testing of phylogeographic models against ancestral genomes from glacial refugia has rarely been possible. Here we compare ND1 mitochondrial DNA variation in late Pleistocene (16,000-40,000 years before present), historical and contemporary Atlantic salmon (Salmo salar) populations from northern Spain and other regions of western Europe. Our study demonstrates the presence of Atlantic salmon in the Iberian glacial refugium during the last 40,000 years and points to the Iberian Peninsula as the likely source of the most common haplotype within the Atlantic lineage in Europe. However, our findings also suggest that there may have been significant changes in the genetic structure of the Iberian refugial stock since the last ice age, and question whether modern populations in refugial areas are representative of ice age populations. A common haplotype that persisted in the Iberian Peninsula during the Pleistocene last glacial maximum is now extremely rare or absent from European rivers, highlighting the need for caution when making phylogeographic inferences about the origin and distribution of modern genetic types.
Collapse
|
47
|
Shompole S, Yao C, Cheng X, Knox D, Johnson S, Jasmer DP. Distinct characteristics of two intestinal protein compartments discriminated by using fenbendazole and a benzimidazole resistant isolate of Haemonchus contortus. Exp Parasitol 2002; 101:200-9. [PMID: 12594960 DOI: 10.1016/s0014-4894(02)00135-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The intestine of Haemonchus contortus is hypersensitive to the effects of the anthelmintic fenbendazole (FBZ). The effects are postulated to stem from disruption of microtubules and interference with apical secretory vesicle transport, followed by release of digestive enzymes into the intestinal cell cytoplasm. Here, FBZ caused marker proteins for both apical (pepsinogen-like protease, PEP-1) and basal (cystatin-like protein) protein compartments to became homogeneously distributed in the cytoplasm of H. contortus intestinal cells. The observations with PEP-1 support the hypothesis that release of hydrolytic enzymes into the intestinal cell cytoplasm contributes to the mechanism of benzimidazole efficacy. A benzimidazole resistant isolate of H. contortus expressed type 1 and 2 intestinal beta-tubulin transcripts that would encode predominantly tyr200 and phe200 variants, respectively. This isolate was resistant to the known intestinal cell alterations induced by FBZ treatment in the susceptible isolate, including inhibition of apical vesicle transport. These results implicate type 1 beta-tubulin in mediating apical vesicle transport in intestinal cells and suggest that the tyr200 variant is a determinant of FBZ resistance in intestinal cells. In contrast, the basal protein compartment demonstrated sensitivity to FBZ treatment in these otherwise "resistant" worms. Hence, distinct FBZ-sensitive components appear to be involved in distributing intestinal proteins into the described apical and basal compartments of normal worms.
Collapse
|
48
|
Knox D, Zusman ME, McGinty K, Gescheidler J. Deception of parents during adolescence. ADOLESCENCE 2002; 36:611-4. [PMID: 11817641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Two hundred eighty-one undergraduates at a large university in the southeastern United States anonymously completed a 26-item questionnaire about the degree to which they deceived their parents during high school. Only five percent of the respondents reported that they had never lied to their parents about "where I was." "Who I was with," "my alcohol use," and "my sexual behavior" were additional topics about which they lied the most. It was also found that (1) females lied more than males about sexual behavior, (2) the opposite-sex parent was deceived more often, and (3) intact homes were associated with more lying. Respondents also reported more lies when they lived with their parents than when they left for college. The implications of the findings are discussed.
Collapse
|
49
|
Kenyon F, Knox D. The proteinases of Psoroptes ovis, the sheep scab mite--their diversity and substrate specificity. Vet Parasitol 2002; 105:317-25. [PMID: 11983306 DOI: 10.1016/s0304-4017(02)00015-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The sheep scab mite, Psoroptes ovis, causes severe dermatitis in infected sheep with severe welfare and production implications. The dermatitis has the characteristics of an immediate hypersensitivity type reaction which, by analogy to other mite species, including the house dust mites (Dermatophagoides spp.), is likely to be invoked by a variety of allergens including mite-derived proteinases. Here, the proteinases in P. ovis extracts were characterised using substrate gel analysis, inhibitor sensitivity and their ability to degrade a variety of potential natural protein substrates. These analyses showed that mites contain several proteinases which could be differentiated on the basis of molecular size and inhibitor sensitivity with cysteine, metalloproteinases and aspartyl proteinases predominating. These proteinases degraded collagen and fibronectin, possibly indicative of a role in lesion initiation, they degraded several blood proteins, a property which may aid mite feeding and they degraded immunoglobulin G, possibly aiding immuno-evasion. Because proteinases, particularly the cysteine class, are demonstrably allergenic in other mite infestations, these proteinases clearly merit further immunological and biochemical definition.
Collapse
|
50
|
Geldhof P, Claerebout E, Knox D, Vercauteren I, Looszova A, Vercruysse J. Vaccination of calves against Ostertagia ostertagi with cysteine proteinase enriched protein fractions. Parasite Immunol 2002; 24:263-70. [PMID: 12060320 DOI: 10.1046/j.1365-3024.2002.00461.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cysteine proteinase enriched fractions obtained by thiol-sepharose chromatography of Ostertagia ostertagi membrane-bound protein extract (S3-thiol) or total adult excretory-secretory (ES-thiol) products were tested in a vaccination experiment to evaluate their protective efficacy against O. ostertagi in cattle. Calves were vaccinated three times and subsequently challenged with a trickled infection of 25,000 infective larvae in total over 25 days (1000 L3/day, 5 days/week). Geometric mean cumulative egg counts in the ES-thiol group were reduced by 60% during the 2-month period between the first challenge infection and necropsy, compared to the control group (P < 0.002). No reduction in egg output was observed in the S3-thiol group. At necropsy, calves immunized with ES-thiol had a significantly higher percentage of inhibited L4 larvae (9.8%) and had in total 18% less worms than the control calves, but this reduction was not statistically significant. Both the female and male adult worms were significantly smaller in the ES-thiol group than in the control group. Although no significant difference was observed in the number of eggs per female worm between the groups, there was a trend to less eggs per female worm in the ES-thiol group. Number of worms, size of adult worms and number of eggs per female worm were not significantly different between the S3-thiol group and the control group. Systemic immunization with QuilA as adjuvant induced a significant rise in Ostertagia-specific antibody levels in the abomasal mucosa. Ostertagia-specific local antibody levels showed a significant negative correlation with the size of the adult worms, the number of eggs per female worm and the cumulative faecal egg counts. However, these correlations were quite weak and did not appear to be isotype-specific.
Collapse
|