scholarly journals Possible mechanisms of host resistance to Haemonchus contortus infection in sheep breeds native to the Canary Islands

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhengyu Guo ◽  
Jorge Francisco González ◽  
Julia N. Hernandez ◽  
Tom N. McNeilly ◽  
Yolanda Corripio-Miyar ◽  
...  
2008 ◽  
Vol 153 (3-4) ◽  
pp. 374-378 ◽  
Author(s):  
Jorge F. González ◽  
Álvaro Hernández ◽  
José M. Molina ◽  
Antonio Fernández ◽  
Herman W. Raadsma ◽  
...  

2000 ◽  
Vol 28 ◽  
pp. 27-34 ◽  
Author(s):  
J.V. Delgado ◽  
R. Perezgrovas ◽  
M.E. Camacho ◽  
M. Fresno ◽  
C. Barba

SummaryWhen the Spaniards discovered and conquered the Canary Islands in the 15th Century, they found a type of hair sheep, a breed described by the colonists as “white in colour, large in size and with horns in the males”. This discovery provokes the question: from where did these sheep originate? All other breeds of wool-less sheep in the world in that period were located in the sub-Saharan regions, far away from the Canary Islands and with no possible connection.Archaeologists claim that Northwest Africa was populated by wool sheep from 4000–3000 BC. Northwest Africa is the nearest geographical point of the African continent to the Canary Archipelago. It was also there that the native pre-Hispanic human population is thought to have originated. Did the wool-less sheep breed arrive with these people? The answer is probably yes. It is likely that the population of hair sheep arrived between 3000–2000 BC in a northern expansion of these animals, accompanying the first inhabitants of the islands.After the Spanish conquest, the Canary Islands provided a necessary stop for the explorers of the New World. Various testimonies exist describing the arrival of the first sheep to the Caribbean Islands. This process of animal introduction started with Columbus′ second voyage, after which domestic animals formed a usual part of the shipment arrangements. This raises a third question: what role did the Canary Island sheep play in the origin and evolution of the present Caribbean and Latin-American hair breeds? The majority of researchers working with these animals in America and the Caribbean think that the origin of their wool-less sheep breeds is related to the traffic of black slaves during the 17th and 18th centuries. It may be claimed that this influence of sub-Saharan animals exists as an additional influence of other wool-less sheep breeds, which arrived in the Caribbean from the Canary Islands two centuries earlier. Today, the ancient native hair sheep breed is extinct in the Canary Islands although some wool-less sheep have recently been introduced from Venezuela.All these questions and ideas are investigated in this paper, through historical references and current research.


1997 ◽  
Vol 69 (3-4) ◽  
pp. 265-273 ◽  
Author(s):  
J.M. Mugambi ◽  
R.K. Bain ◽  
S.W. Wanyangu ◽  
M.A. Ihiga ◽  
J.L. Duncan ◽  
...  

2015 ◽  
Vol 47 (5) ◽  
pp. 961-968 ◽  
Author(s):  
Tesfaye Getachew ◽  
Biruk Alemu ◽  
Johann Sölkner ◽  
Solomon Gizaw ◽  
Aynalem Haile ◽  
...  

2010 ◽  
Vol 168 (1-2) ◽  
pp. 141-145 ◽  
Author(s):  
H.A. Saddiqi ◽  
Z. Iqbal ◽  
M.N. Khan ◽  
M. Sarwar ◽  
G. Muhammad ◽  
...  

Author(s):  
Egbert W. Henry

Tobacco mosaic virus (TMV) infection has been studied in several investigations of Nicotiana tabacum leaf tissue. Earlier studies have suggested that TMV infection does not have precise infective selectivity vs. specific types of tissues. Also, such tissue conditions as vein banding, vein clearing, liquification and suberization may result from causes other than direct TMV infection. At the present time, it is thought that the plasmodesmata, ectodesmata and perhaps the plasmodesmata of the basal septum may represent the actual or more precise sites of TMV infection.TMV infection has been implicated in elevated levels of oxidative metabolism; also, TMV infection may have a major role in host resistance vs. concentration levels of phenolic-type enzymes. Therefore, enzymes such as polyphenol oxidase, peroxidase and phenylalamine ammonia-lyase may show an increase in activity in response to TMV infection. It has been reported that TMV infection may cause a decrease in o-dihydric phenols (chlorogenic acid) in some tissues.


1990 ◽  
Vol 78 (4) ◽  
pp. 609-615 ◽  
Author(s):  
Bruno M. Moerschbacher ◽  
Ulrike Noll ◽  
Carlos A. Ocampo ◽  
Berenike E. Flott ◽  
Uwe Gotthardt ◽  
...  

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
LDR Oliveira ◽  
JPHV Miranda ◽  
GS Curado ◽  
JP Costa Neto ◽  
BF Santos ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document