scholarly journals Ancient Hybridization and Adaptive Introgression of an Invadolysin Gene in Schistosome Parasites

2019 ◽  
Vol 36 (10) ◽  
pp. 2127-2142 ◽  
Author(s):  
Roy N Platt ◽  
Marina McDew-White ◽  
Winka Le Clec’h ◽  
Frédéric D Chevalier ◽  
Fiona Allan ◽  
...  
Keyword(s):  
High Frequency ◽  
Parasite Species ◽  
Single Gene ◽  
Sub Saharan Africa ◽  
Species Boundaries ◽  
Urogenital Schistosomiasis ◽  
Adaptive Introgression ◽  
Introgression Event ◽  
Sub Saharan ◽  
Ancient Hybridization

Abstract Introgression among parasite species has the potential to transfer traits of biomedical importance across species boundaries. The parasitic blood fluke Schistosoma haematobium causes urogenital schistosomiasis in humans across sub-Saharan Africa. Hybridization with other schistosome species is assumed to occur commonly, because genetic crosses between S. haematobium and livestock schistosomes, including S. bovis, can be staged in the laboratory, and sequencing of mtDNA and rDNA amplified from microscopic miracidia larvae frequently reveals markers from different species. However, the frequency, direction, age, and genomic consequences of hybridization are unknown. We hatched miracidia from eggs and sequenced the exomes from 96 individual S. haematobium miracidia from infected patients from Niger and the Zanzibar archipelago. These data revealed no evidence for contemporary hybridization between S. bovis and S. haematobium in our samples. However, all Nigerien S. haematobium genomes sampled show hybrid ancestry, with 3.3–8.2% of their nuclear genomes derived from S. bovis, providing evidence of an ancient introgression event that occurred at least 108–613 generations ago. Some S. bovis-derived alleles have spread to high frequency or reached fixation and show strong signatures of directional selection; the strongest signal spans a single gene in the invadolysin gene family (Chr. 4). Our results suggest that S. bovis/S. haematobium hybridization occurs rarely but demonstrate profound consequences of ancient introgression from a livestock parasite into the genome of S. haematobium, the most prevalent schistosome species infecting humans.

scholarly journals Ancient hybridization and introgression of an invadolysin gene in schistosome parasites

2019 ◽  
Author(s):  
Roy N. Platt ◽  
Marina McDew-White ◽  
Winka Le Clec’h ◽  
Frederic D. Chevalier ◽  
Fiona Allan ◽  
...  
Keyword(s):  
Life History ◽  
Schistosoma Haematobium ◽  
Life History Traits ◽  
Single Gene ◽  
Sub Saharan Africa ◽  
Urogenital Schistosomiasis ◽  
Introgression Event ◽  
Sub Saharan ◽  
Hybridization And Introgression ◽  
Ancient Hybridization

The parasitic blood fluke Schistosoma haematobium causes urogenital schistosomiasis in humans and is a major cause of morbidity and mortality across sub-Saharan Africa. S. haematobium hybridizes with livestock schistosomes, including S. bovis, however the frequency, direction, age and genomic consequences of hybridization are unknown. We sequenced 96 S. haematobium exomes from Niger and the Zanzibar archipelago. and found evidence of an ancient, introgression event between Nigerien S. haematobium and S. bovis occurring 108-613 generations ago. Between 3.3-8.2% of Nigerien S. haematobium genomes are derived from S. bovis alleles, some of which show signatures of directional selection; the strongest signal spans a single gene in the invadolysin gene family, an M8 metalloprotease associated with parasitic life-history traits.

scholarly journals Correction to: The diagnosis and treatment of urogenital schistosomiasis in Italy in a retrospective cohort of immigrants from Sub-Saharan Africa

Infection ◽  
2019 ◽  
Vol 47 (3) ◽  
pp. 461-462
Author(s):  
Marta Tilli ◽  
Federico Gobbi ◽  
Francesca Rinaldi ◽  
Jacopo Testa ◽  
Silvio Caligaris ◽  
...  
Keyword(s):  
Retrospective Cohort ◽  
Sub Saharan Africa ◽  
Diagnosis And Treatment ◽  
Urogenital Schistosomiasis ◽  
Sub Saharan

scholarly journals The potentially deleterious functional variant flavin-containing monooxygenase 2*1 is at high frequency throughout sub-Saharan Africa

2008 ◽  
Vol 18 (10) ◽  
pp. 877-886 ◽  
Author(s):  
Krishna R. Veeramah ◽  
Mark G. Thomas ◽  
Michael E. Weale ◽  
David Zeitlyn ◽  
Ayele Tarekegn ◽  
...  
Keyword(s):  
High Frequency ◽  
Sub Saharan Africa ◽  
Functional Variant ◽  
Sub Saharan

scholarly journals Recovering signals of ghost archaic introgression in African populations

2018 ◽  
Author(s):  
Arun Durvasula ◽  
Sriram Sankararaman
Keyword(s):  
High Frequency ◽  
Substantial Contribution ◽  
Genome Sequences ◽  
Modern Humans ◽  
Frequency Spectra ◽  
Adaptive Introgression ◽  
Genome Wide ◽  
African Populations ◽  
Archaic Introgression ◽  
Sub Saharan

AbstractWhile introgression from Neanderthals and Denisovans has been well-documented in modern humans outside Africa, the contribution of archaic hominins to the genetic variation of present-day Africans remains poorly understood. Using 405 whole-genome sequences from four sub-Saharan African populations, we provide complementary lines of evidence for archaic introgression into these populations. Our analyses of site frequency spectra indicate that these populations derive 2-19% of their genetic ancestry from an archaic population that diverged prior to the split of Neanderthals and modern humans. Using a method that can identify segments of archaic ancestry without the need for reference archaic genomes, we built genome-wide maps of archaic ancestry in the Yoruba and the Mende populations that recover about 482 and 502 megabases of archaic sequence, respectively. Analyses of these maps reveal segments of archaic ancestry at high frequency in these populations that represent potential targets of adaptive introgression. Our results reveal the substantial contribution of archaic ancestry in shaping the gene pool of present-day African populations.One sentence summaryMultiple present-day African populations inherited genes from an unknown archaic population that diverged before modern humans and Neanderthals split.

scholarly journals Cytological and Wet Mount Microscopic Observations Made in Urine of Schistosoma haematobium-Infected Children: Hint of the Implication in Bladder Cancer

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Patience B. Tetteh-Quarcoo ◽  
Benjamin K. Akuetteh ◽  
Irene A. Owusu ◽  
Solomon E. Quayson ◽  
Simon K. Attah ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Schistosoma Haematobium ◽  
Inflammatory Cells ◽  
Sub Saharan Africa ◽  
Urine Samples ◽  
Urogenital Schistosomiasis ◽  
Cytological Abnormalities ◽  
Sub Saharan ◽  
Carcinoma Of The Bladder ◽  
Infected Urine

Background. Schistosomiasis is the second major human parasitic disease next to malaria, in terms of socioeconomic and public health consequences, especially in sub-Saharan Africa. Schistosoma haematobium (S. haematobium) is a trematode and one of the species of Schistosoma that cause urogenital schistosomiasis (urinary schistosomiasis). Although the knowledge of this disease has improved over the years, there are still endemic areas, with most of the reported cases in Africa, including Ghana. Not much has been done in Ghana to investigate cytological abnormalities in individuals within endemic communities, although there are epidemiologic evidences linking S. haematobium infection with carcinoma of the bladder. Aim. The aim of this study was to identify microscopic and cytological abnormalities in the urine deposits of S. haematobium-infected children. Methodology. Three hundred and sixty-seven (367) urine samples were collected from school children in Zenu and Weija communities. All the samples were examined microscopically for the presence of S. haematobium eggs, after which the infected samples and controls were processed for cytological investigation. Results. S. haematobium ova were present in 66 (18.0%) out of the 367 urine samples. Inflammatory cells (82%, 54/66), hyperkeratosis (47%, 31/66), and squamous cell metaplasia (24%, 16/66) were the main observations made during the cytological examination of the S. haematobium-infected urine samples. Conclusion. Cytological abnormalities in S. haematobium-infected children may play an important role in the severity of the disease, leading to the possible development of bladder cancer in later years, if early attention is not given. Therefore, routine cytological screening for urogenital schistosomiasis patients (especially children) at hospitals in S. haematobium-endemic locations is recommended.

Disorders of the synthesis or function of haemoglobin

2010 ◽  
pp. 4420-4445
Author(s):  
D.J. Weatherall
Keyword(s):  
Mediterranean Region ◽  
Single Gene ◽  
International Travel ◽  
Sub Saharan Africa ◽  
Inherited Disorders ◽  
Single Gene Disorders ◽  
High Incidence ◽  
The World ◽  
Haemoglobin Disorders ◽  
Sub Saharan

The inherited disorders of haemoglobin are the commonest single-gene disorders in the world. They cause much morbidity and mortality in those individuals who are severely affected, and place a major burden on health services in some places, in particular the Mediterranean region, sub-Saharan Africa, and South-East Asia, when economic conditions improve and infant and childhood death rates fall. Mass migrations of populations from high-incidence areas for the haemoglobin disorders, together with the general ease of international travel, means that these conditions are being seen with increasing frequency in parts of the world where they have not been recognized previously....

The diagnosis and treatment of urogenital schistosomiasis in Italy in a retrospective cohort of immigrants from Sub-Saharan Africa

Infection ◽  
2019 ◽  
Vol 47 (3) ◽  
pp. 447-459 ◽  
Author(s):  
Marta Tilli ◽  
Federico Gobbi ◽  
Francesca Rinaldi ◽  
Jacopo Testa ◽  
Silvio Caligaris ◽  
...  
Keyword(s):  
Retrospective Cohort ◽  
Sub Saharan Africa ◽  
Diagnosis And Treatment ◽  
Urogenital Schistosomiasis ◽  
Sub Saharan

scholarly journals Immunological Consequences of Antihelminthic Treatment in Preschool Children Exposed to Urogenital Schistosome Infection

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Nadine Rujeni ◽  
Norman Nausch ◽  
Nicholas Midzi ◽  
Graeme J. Cowan ◽  
Richard Burchmore ◽  
...  
Keyword(s):  
Young Age ◽  
Preschool Age ◽  
Antibody Responses ◽  
Sub Saharan Africa ◽  
Older Individuals ◽  
Urogenital Schistosomiasis ◽  
Control Programs ◽  
Praziquantel Treatment ◽  
Effect Of Treatment ◽  
Sub Saharan

Urogenital schistosomiasis, due toSchistosoma haematobium,is endemic in sub-Saharan Africa. Control is by targeted treatment with praziquantel but preschool age children are excluded from control programs. Immunological studies on the effect of treatment at this young age are scarce. In light of studies in older individuals showing that praziquantel alters antischistosome immune responses and responses to bystander antigens, this study aims to investigate how these responses would be affected by treatment at this young age. Antibody responses directed against schistosome antigens,Plasmodium falciparumcrude and recombinant antigens, and the allergen house dust mite were measured in children aged 3 to 5 years before and 6 weeks after treatment. The change in serological recognition of schistosome proteins was also investigated. Treatment augmented antischistosome IgM and IgE responses. The increase in IgE responses directed against adult worm antigens was accompanied by enhanced antigen recognition by sera from the children. Antibody responses directed againstPlasmodiumantigens were not significantly affected by praziquantel treatment nor were levels of allergen specific responses. Overall, praziquantel treatment enhanced, quantitatively and qualitatively, the antiworm responses associated with protective immunity but did not alterPlasmodium-specific responses or allergen-specific responses which mediate pathology in allergic disease.

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