17095
Strain - dependent down - regulation of several key one - carbon metabolism genes , including methionine adenosyltransferase 1 alpha ( Mat1a ) , cystathionine - beta - synthase ( Cbs ) , methylenetetrahydrofolate reductase ( Mthfr ) , adenosyl - homocysteinase ( Ahcy ) , and methylenetetrahydrofolate dehydrogenase 1 ( Mthfd1 ) , was observed .
 Chemical: carbon; Chemical: methionine; Chemical: cystathionine; Chemical: methylenetetrahydrofolate; Chemical: adenosyl; Chemical: methylenetetrahydrofolate
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: carbon; Chemical: methionine; Chemical: cystathionine; Chemical: methylenetetrahydrofolate; Chemical: adenosyl; Chemical: methylenetetrahydrofolate