Questions regarding our posted article:

Question 1 - multipart:
a.)  Which species of Schistosoma have been sequenced?
b.)  For each species, list the number of haploid chromosomes, the genome size, GC content, number of genes, and number of proteins.
c.) Are the answers for each of these species similar? Why? Why study these three species?

Answer 1
Schistosoma mansoni 

1. # of haploid chromosomes:  8
2. Genome size: 258.72
3. GC content: 35%
4. Number of genes: 11,332 
5. Number of proteins: 8,293 

Schistosoma japonicum

1. # of haploid chromosomes: 8
2. Genome size: 369.09
3. GC content: 34.1%
4. Number of genes: N/A 
5. Number of proteins: N/A

Schistosoma heamatobium

1. #of haploid chromosomes:  N/A
2. Genome size: N/A
3. GC content: N/A
4. Number of genes: N/A
5. Number of proteins: N/A 

The genmone size of Mansoni and japonicum are different by over a hundred Mb's. However, their GC content is almost identical. They also both have 8 haploid chromosomes. These characteristics are similar because they are closely related organisms. They may have differences because they may have undergone evolutionary changes in order to better infect their hosts. They may also be different because they live in different environments.

Question 2:

What type of markers were used to establish linkage groups in this study?  Why is it important, in an evolutionary sense, to identify linkage groups?

Answer:

In this study, eight types of markers that were consistent with chromosome numbers were used to establish the linkage groups of Schistosomes.  Linkage groups were identified and anchored to the chromosomes using fluorescent in situ hybridization (FISH).  By identifying the linkage groups, higher female recombination, confirmed ZW inheritance patterns, identified recombination hotpots and regions of segregation distortion were identified. 

Identifying linkage groups is very important in an evolutionary sense because it highlights the incidence of traits being inherited together.  Thus, traits that are selected for in future generations are often linked to other traits that may be also inherited, with or without beneficial contribution of fitness.  As far as the study, linkage has proved very helpful in establishing the genome map

Question 3:

Visit http://schistoDB.org On the right, click on “Browse S. mansoni v5.0 Chromosome 6”.  Click on a colored part of the high-level map of chromosome 6.  What gene is it?  What does it code for?

Answer:

 It is a protein-coding gene and it’s systematic name is Smp_095880, which codes for a hypothetical protein.

Question 4:

Why is it important to study protein folding/misfolding in schistosomes? (refer to p. 157 of your paper for guidance)

Answer:

It is important to study protein folding/ misfolding in schistosomes because it may be a key in preventing the successful reproduction and regeneration of schistosomes both within the human body and within that of a host’s body.  When proteins are translated from mRNA to produce an amino acid chain, the protein remains non-functional until it is properly folded into the standard double helix form of DNA.  By studying the base pair positioning and being able to influence the order of amino acid base pairs, researchers may be able to prevent the proper folding (or misfolding) of proteins, thus affecting the fitness of schistosomes by causing mutations and non-functional genes.