The major parasitic platyhelminth classes ? progressive or regressive evolution?

Hydrobiologia ◽  
1986 ◽  
Vol 132 (1) ◽  
pp. 23-29 ◽  
Author(s):  
G. Malmberg
Keyword(s):  
Regressive Evolution ◽  
Parasitic Platyhelminth

Regressive evolution of an effector following a host jump in the Irish Potato Famine Pathogen Lineage

2021 ◽  
Author(s):  
Erin K. Zess ◽  
Yasin F. Dagdas ◽  
Esme Peers ◽  
Abbas Maqbool ◽  
Mark J. Banfield ◽  
...  
Keyword(s):  
Host Species ◽  
Irish Potato ◽  
Sequence Motif ◽  
New Host ◽  
Regressive Evolution ◽  
Host Environment ◽  
Host Jump ◽  
Potato Famine ◽  
Irish Potato Famine ◽  
New Host Species

AbstractIn order to infect a new host species, the pathogen must evolve to enhance infection and transmission in the novel environment. Although we often think of evolution as a process of accumulation, it is also a process of loss. Here, we document an example of regressive evolution in the Irish potato famine pathogen (Phytophthora infestans) lineage, providing evidence that a key sequence motif in the effector PexRD54 has degenerated following a host jump. We began by looking at PexRD54 and PexRD54-like sequences from across Phytophthora species. We found that PexRD54 emerged in the common ancestor of Phytophthora clade 1b and 1c species, and further sequence analysis showed that a key functional motif, the C-terminal ATG8-interacting motif (AIM), was also acquired at this point in the lineage. A closer analysis showed that the P. mirabilis PexRD54 (PmPexRD54) AIM appeared unusual, the otherwise-conserved central residue mutated from a glutamate to a lysine. We aimed to determine whether this PmPexRD54 AIM polymorphism represented an adaptation to the Mirabilis jalapa host environment. We began by characterizing the M. jalapa ATG8 family, finding that they have a unique evolutionary history compared to previously characterized ATG8s. Then, using co-immunoprecipitation and isothermal titration calorimetry assays, we showed that both full-length PmPexRD54 and the PmPexRD54 AIM peptide bind very weakly to the M. jalapa ATG8s. Through a combination of binding assays and structural modelling, we showed that the identity of the residue at the position of the PmPexRD54 AIM polymorphism can underpin high-affinity binding to plant ATG8s. Finally, we conclude that the functionality of the PexRD54 AIM was lost in the P. mirabilis lineage, perhaps owing to as-yet-unknown pressure on this effector in the new host environment.Author SummaryPathogens evolve in concert with their hosts. When a pathogen begins to infect a new host species, known as a “host jump,” the pathogen must evolve to enhance infection and transmission. These evolutionary processes can involve both the gain and loss of genes, as well as dynamic changes in protein function. Here, we describe an example of a pathogen protein that lost a key functional domain following a host jump, a salient example of “regressive evolution.” Specifically, we show that an effector protein from the plant pathogen Phytopthora mirabilis, a host-specific lineage closely related to the Irish potato famine pathogen Phytopthora infestans, has a derived amino acid polymorphism that results in a loss of interaction with certain host machinery.

Vestigial Characters of Termites and Processes of Regressive Evolution

Evolution ◽  
1961 ◽  
Vol 15 (2) ◽  
pp. 115 ◽  
Author(s):  
Alfred E. Emerson
Keyword(s):  
Regressive Evolution

Neuropeptide F (Moniezia expansa): localization and characterization using specific antisera

Parasitology ◽  
1992 ◽  
Vol 105 (3) ◽  
pp. 505-512 ◽  
Author(s):  
A. G. Maule ◽  
C. Shaw ◽  
D. W. Halton ◽  
G. P. Brennan ◽  
C. F. Johnston ◽  
...  
Keyword(s):  
Confocal Scanning Laser Microscopy ◽  
Specific Antisera ◽  
Scanning Laser Microscopy ◽  
Confocal Scanning ◽  
Immunocytochemical Techniques ◽  
Neuropeptide F ◽  
Moniezia Expansa ◽  
Confocal Scanning Laser ◽  
First Time ◽  
Parasitic Platyhelminth

SUMMARYImmunocytochemical techniques used in conjunction with confocal scanning laser microscopy (CSLM) and electron microscopy have been used to demonstrate, for the first time, the distribution of the parasitic platyhelminth neuropeptide, neuropeptide F (NPF) in the cestode, Moniezia expansa. Antisera were raised to intact NPF(1–39) and to the C-terminal decapeptide of NPF(30–39). These antisera were characterized and validated for use in both immunocytochemistry and radioimmunoassay (RIA). NPF immunoreactivity (IR) was detected using both antisera throughout all of the major components of the central and peripheral nervous systems of the worm. The pattern of NPF-IR was found to mirror the IR obtained using a C-terminally directed pancreatic polypeptide (PP) antiserum and FMRFamide antisera; blocking studies using these antisera revealed that FMRFamide and PP antisera cross-react with NPF(M. expansa). RIA of acid-alcohol extracts of the worm measured 114 ng/g using the C-terminal NPF antiserum and 56 ng/g using the whole-molecule-directed antiserum. While the C-terminally-directed NPF antiserum cross-reacts with NPF-related peptides from other invertebrates, the whole-molecule-directed NPF antiserum is specific for NPF(M. expansa). The C-terminal NPF antiserum has potential for use in the identification and purification of NPF analogues from other platyhelminth parasites.

scholarly journals Synonymous codon usage patterns in different parasitic platyhelminth mitochondrial genomes

2013 ◽  
Vol 12 (1) ◽  
pp. 587-596 ◽  
Author(s):  
L. Chen ◽  
D.Y. Yang ◽  
T.F. Liu ◽  
X. Nong ◽  
X. Huang ◽  
...  
Keyword(s):  
Codon Usage ◽  
Synonymous Codon ◽  
Synonymous Codon Usage ◽  
Mitochondrial Genomes ◽  
Usage Patterns ◽  
Parasitic Platyhelminth

scholarly journals Regressive evolution of the arthropod tritocerebral segment linked to functional divergence of the Hox gene labial

2015 ◽  
Vol 282 (1814) ◽  
pp. 20151162 ◽  
Author(s):  
Matthias Pechmann ◽  
Evelyn E. Schwager ◽  
Natascha Turetzek ◽  
Nikola-Michael Prpic
Keyword(s):  
Functional Divergence ◽  
Functional Change ◽  
Pleiotropic Effects ◽  
Limb Loss ◽  
Evolutionary Origin ◽  
Common Mechanism ◽  
Developmental Genes ◽  
Regressive Evolution ◽  
Hox Gene ◽  
Parasteatoda Tepidariorum

The intercalary segment is a limbless version of the tritocerebral segment and is present in the head of all insects, whereas other extant arthropods have retained limbs on their tritocerebral segment (e.g. the pedipalp limbs in spiders). The evolutionary origin of limb loss on the intercalary segment has puzzled zoologists for over a century. Here we show that an intercalary segment-like phenotype can be created in spiders by interfering with the function of the Hox gene labial . This links the origin of the intercalary segment to a functional change in labial . We show that in the spider Parasteatoda tepidariorum the labial gene has two functions: one function in head tissue maintenance that is conserved between spiders and insects, and a second function in pedipalp limb promotion and specification, which is only present in spiders. These results imply that labial was originally crucial for limb formation on the tritocerebral segment, but that it has lost this particular subfunction in the insect ancestor, resulting in limb loss on the intercalary segment. Such loss of a subfunction is a way to avoid adverse pleiotropic effects normally associated with mutations in developmental genes, and may thus be a common mechanism to accelerate regressive evolution.

Cancer: Regressive Evolution?

Oncology ◽  
1974 ◽  
Vol 29 (2) ◽  
pp. 172-180
Author(s):  
Justin V. Schwind
Keyword(s):  
Regressive Evolution

Acquired von Willebrand’s Syndrome in the Course of Waldenström’s Disease

1980 ◽  
Vol 44 (03) ◽  
pp. 115-118 ◽  
Author(s):  
Claudine Mazurier ◽  
Armelle Parquet-Gernez ◽  
Jacques Descamps ◽  
Francis Bauters ◽  
Maurice Goudemand
Keyword(s):  
Regressive Evolution ◽  
Cofactor Activity ◽  
Auto Antibody ◽  
Ristocetin Cofactor ◽  
Serum Fractionation ◽  
Ristocetin Cofactor Activity

SummaryAcquired von Willebrand's syndrome with a regressive evolution is described in a 66 year old man with Waldenström's disease. An inhibitor electively directed against Ristocetin cofactor activity has been demonstrated, active in vitro after incubation at 37° C. Serum fractionation showed that the inhibitor was independant of the monoclonal IgM and subsequent purification that it was IgG in nature. The results permit its classification as an auto-antibody.

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