Human T-cell leukemia virus type I (HTLV-I) is associated with adult T-cell leukemia/lymphoma and tropical spastic paraparesis/HTLV-associated myelopathy. Both diseases are usually preceded by a long clinically asymptomatic period. PCR amplification of the HTLV-I proviral integration sites shows that clonal expansion of HTLV-I-bearing T cells, rather than being an occasional phenomenon in nonma...

Clonal selection was a natural choice mode of immune system, in which the antibody with high affinity for antigen was promoted and the antibody with low affinity was restrained under the action of clonal selection mechanism. And Clonal Selection Algorithm (CSA) as one kind of searching methods adopted group search strategy, exchanged information between antibodies and achieved global optimal so...

A total of 83 cirrhotic nodules (pseudolobules) individually collected from 11 cirrhotic livers of hepatitis B virus carrier patient were analyzed for the frequency and mode of hepatitis B virus integration as well as histological features. Southern blot analysis disclosed discrete bands at higher molecular weight region in 26 of 83 nodules (31.3%), indicating a clonal growth of hepatocytes wit...

Long-lived understory herbs experience a highly dynamic forest over space and time, yet can persist for more than a century. To understand how these populations persist, we examined effects of forest age and disturbance on potential sexual reproduction and clonal growth in the sexually labile perennial, Arisaema triphyllum. Potential sexual reproduction female:male ratio was significantly great...

Toxoplasma gondii is a highly successful protozoan parasite that infects all warm-blooded animals and causes severe disease in immunocompromised and immune-naïve humans. It has an unusual global population structure: In North America and Europe, isolated strains fall predominantly into four largely clonal lineages, but in South America there is great genetic diversity and the North American clo...

The fitness costs of reproduction by clonal growth can include a limited ability to adapt to environmental and temporal heterogeneity. Paradoxically, some facultatively clonal species are not only able to survive, but colonize, thrive and expand in heterogeneous environments. This is likely due to the capacity for acclimation (sensu stricto) that compensates for the fitness costs and complement...