Semiotics : study of signs :: memetics : study of memes. What semiotics is to signs and the study of signs, memetics is to memes and the study of memes.
a sign can be a meme. but a meme is more than just a sign. ideologies and religions are forms of memes. they can also bleed into the corporeal realm, and create "artefacts", art, culture.
semiotics was later called structuralist, here is a paper on the interaction of structural semiotics and memetics
from the above source : "Memes are powerful propagators of meanings, of practices, beliefs and their critique, and as such play a vital role in inventorying and categorizing our cultural memory. Susan Blackmore regards memes as “substrate-neutral” (1999: 11), however, as mindless events or algorithms based on the logics or syntax of procedure or even on an ‘innate’ universal grammar." 
hegel thought of structures however memetics is more pervasive
memetics and semiotics
"reality is understood to be composed of fictions — semiotic terrains => perceptual, affective, and behavioral responses."]
also see : umwelt