Nutritional upgrading for omnivorous carpenter ants by the endosymbiont Blochmannia

Table 1 ¹⁵N-labelling of free amino acids in the hemolymph of ants fed with [¹⁵N] urea

	Calculated natural abundance	Urea feeding experiments (control)		[¹⁵N]Urea feeding experiments (labelling)
	M+1 abundance (fraction %)	M+1 abundance (fraction %)	[¹⁵N]AA (mol %)	M+1 abundance (fraction %)	[¹⁵ N]AA (mol %)
Gly	7.6	6.8 ± 0.3	-0.8 ± 0.3	11.7 ± 0.8	4.2 ± 0.8
Ala	8.5	7.8 ± 0.6	-0.7 ± 0.6	16.7 ± 1.8	8.2 ± 1.9
Glu	11.1	10.4 ± 0.3	-0.8 ± 0.3	20.1 ± 2.5	8.9 ± 2.5
Asp	10.3	9.6 ± 0.2	-0.7 ± 0.2	16.1 ± 1.7	5.8 ± 1.7
Met	10.4	10.8 ± 1.1	0.4 ± 1.1	13.4 ± 0.9	3.0 ± 0.9
Phe	12.5	11.8 ± 0.3	-1.7 ± 0.3	16.4 ± 1.2	2.9 ± 1.2

After feeding experiments, free amino acids (AA) from hemolymph of 4–6 ants were derivatized and analyzed by GC-MS. The abundance of the first isotope peak, i.e. the amount of naturally occurring AA containing a heavy isotope (either ¹³C or ¹⁵N; M + 1) was determined from the mass spectra of amino acids, and additional ¹⁵N-incorporation (mol %) was calculated. Both non-essential and essential (bold) AA were found to be labelled. Values are obtained from at least three independent experiments and relative amount averaged over samples (mean ± SE).

ISSN: 1741-7007